VC8145 thread ... It's here, finally

[T4P]

I'll post a preliminary picture first, i guess i got to do a teardown soon as i'm flying off to japan in a few days
But ... check out the built in temperature resolution!  (The thermocouple mode is entered by hitting "SELECT" and it goes to 0.1C resolution)

[Wytnucls]

Temperature to the 10th of of a degree...Whoa!...That will be real handy to keep the claret at the right temperature in that built-in wine cellar.

[videobruce]

Ok, there are 10 different pieces of equip. in that pic, which one is this VC8145?? 

[ciccio]

Does it measure dB?
I understand this reading the manufacturer's specifications, but they are absolutely NOT clear.
Does a forum member have a manual to share?
Thank

[alm]

The PDF manual is available from Aidetek:
http://www.aidetek.com/New_products_info/Photo/Vichy/VC8145_English_manual.pdf

It mentions dBm as a secondary function in AC/DCV mode with several choices of reference impedance. Unless you use it frequently, you might as well get out your calculator and calculate the dBm value from the voltage.

One thing I noticed in the manual is that the ACV accuracy is beyond terrible for values > 75% of each range: 8% of reading + 50 digits. Also note that ACV is only specified for frequencies >= 50 Hz.

[Rick]

Temperature to the 10th of of a degree...Whoa!...That will be real handy to keep the claret at the right temperature in that built-in wine cellar.

They could have made the box smaller, couldn't they?
Is it possible to fill that space with something useful for the multimeter?

[grenert]

Is it possible to fill that space with something useful for the multimeter?

You could tuck a Fluke 87V in there.

[david77]

What's the point of this meter?

[T4P]

Ok, there are 10 different pieces of equip. in that pic, which one is this VC8145??

The bench one 

So far i'm loving it, don't really like the boot time so much and not so much of the annoying startup sound, it's exactly like those nokia stock ringtones so annoying
But the built in square wave gen is pretty much quite accurate, down to 1% duty per step and yet it's very close except 90% onwards where it goes out nought-point-something percent

What's the point of this meter?

Bench? Don't need to worry about batteries when i'm logging to my PC neither do i need to worry about a backlight draining a battery (which i never had)

[Rick]

Is it possible to fill that space with something useful for the multimeter?

You could tuck a Fluke 87V in there.

Actually, when you think, it is better to buy a good brand new bench multimeter like that than buying a used Fluke or a HP 3478A from all sorts of crooks on ebay who never admit their device has some defect. And I notice people suffer to repair their old equipment. This is pathetic. I was planning to buy that VC8145 too but after they pointed out the inaccuracy in the AC range may be I shall go for the more expensive UNI-T UT805A with 5 1/2 digit resolution. After all it has also plenty of space in which I can tuck my Fluke 87V

[Rick]

Is it possible to fill that space with something useful for the multimeter?

You could tuck a Fluke 87V in there.

Seriously, I was thinking about some sort of hack or improvement...

[alm]

Actually, when you think, it is better to buy a good brand new bench multimeter like that than buying a used Fluke or a HP 3478A from all sorts of crooks on ebay who never admit their device has some defect.

I'm not so sure, if you call Vichy or Uni-T bench meters 'good'. Of course you might get a lemon HP/Fluke, but at least you know it was well designed and worked well at some point in time. The UI will be well thought out. The specs were probably much better, and many of the instruments are still in or close to the 1 year specs 10+ years after calibration. If it is still working after all this years, then it's unlikely to die anytime soon.

I wouldn't want to vouch for this meter being in spec right after being shipped from the factory. Depending on where you bought it (some shady outfit on eBay?) and where you live, warranty or returning may not turn out to be a useful option either.

[Rick]

All of the Chinese sellers I came across and bought items from turned out to be more or less good ones. When the items were defective I got at least a partial refund or a replacement was sent.
On the other hand when you receive a faulty product of a good brand it doesn't mean anything. You just lose your money.
I came across wonderfull sellers from USA but there are cheaters too. Especially those who sell used products. Fluke is a great brand, I agree as I have had the chance to try several of their handheld multimeters. But if the used product is defective and the seller does not tell the entire truth about his product, it doesn't mean anything. Now if someone wants to buy a new Fluke, that's great, but buying a used multimeter on ebay is not something I shall do again, just like I would not buy a used computer (I did it twice on the local market and in each case there was some defect).

[alm]

I'm not so much worried about a cheap DMM being outright defective, but more about it being unusable due to some stupid design issues. Sellers are less willing to give refunds for design flaws, and returning it is often quite expensive since shipping from at least Western countries to China is much more expensive than the other way around. Uni-T products have turned out to have a very variable quality, and I haven't heard of any good Vichy products yet. Opinions on the VC99 range from crap to OK for its price.

I have bought almost all of my test equipment used and have only had a few undisclosed defects that turned out to be fixable (all of the DMMs were fine and almost all were in spec). Of course I've had as-is/untested equipment that turned out to be defective. However, I'm not going to pretend to derive any odds from anecdotes.

With new equipment like this VC8145 you might either get an unusable piece of crap (ok, you might get a lunch box out of it) or a mediocre product. With a used HP 3478A you might either get a broken piece of equipment that may or may not be fixable or an excellent instrument. In both cases you might or might not be able to get a (partial) refund. Some Chinese ebay sellers are willing to give refunds for crap products, and some used equipment sellers also stand behind their products.

[Wytnucls]

Capacitance measurement accuracy is a joke, worthy of a 4,000 count meter only.
There is no cap discharge function, so you'd better make sure all caps are discharged before testing!
Also, I wonder how long it's going to last before the meter blows its mVolt range ADC:
What a P.O.S! 

[BravoV]

What's the point of this meter?

A benchtop meter with built in lunch box ? 

[Wytnucls]

Yes, all you have here is a mediocre 30.00$ DMM PCB, hooked up to an 8.00$ transformer, placed in a huge plastic box, selling for 140.00$. Vichy must be laughing all the way to the bank with this one. 

[T4P]

You came here just to knock the damn thing 
It's more than just 30$, it's not that SIMPLE god damn it
Do you have AutoHold with another chinese HH DMM? It works here for god's sake, DO YOU HAVE IT ON YOUR DMMs?
Mediocre? Does any of your meters have 10 digit frequency resolution? Rising edge duty cycle, falling edge duty cycle, rising edge time falling edge time so that you don't need a calculator on every reading! All covered. Oh how about 8Gohms capability?

Damn it, you guys came here just to knock it like SERIOUSLY?

[Rick]

... and returning it is often quite expensive since shipping from at least Western countries to China is much more expensive than the other way around.

Returning an item to USA from overseas is also very expensive believe me.
And they often set a 14 day return limit.
You may return it to the seller and not get a refund because of an equipment which arrives late at destination.
For people in USA it may be interesting to buy such multimeters or for those who sell in their own country like in Australia, UK, Germany, France or Netherlands.
When you buy a faulty equipment from USA and you live elsewhere it is always a pain to return it.

[alm]

Also, I wonder how long it's going to last before the meter blows its mVolt range ADC:

I don't understand this statement in the manual:

3.At millivoltage measurement mode in order to obtain DC+AC function , the input terminal o ADC do not employed coupling capacitor. Therefor please never apply more than double the dc or ac voltage of the rated value of this range.

Of course DC or DC+AC measurements are not AC coupled, and what does a coupling capacitor have to do with the maximum allowed AC voltage? Is this the result of the Engrish translation?

If the 80 mV range can only tolerate up to 160 mV, then this should be something to watch out for. Especially since the input is labeled just max. 1000 VDC / 750 VAC, CAT II 1000 V.

Mediocre? Does any of your meters have 10 digit frequency resolution?

Quantity of features does not equal quality. Admittedly your are probably the only one on this forum with access to this instrument, so the only information we have available is a few pictures and a crappy manual. According to the manual the 10 digit resolution is only for frequencies above 10 MHz with the high frequency accessory, is it included or do you have to pay extra? Too bad they didn't include a decent crystal oscillator time base, accuracy for frequency is only 0.05/0.1 % + 5 counts (so those other 5 digits are mostly for show). They don't have the power constraints of hand held DMMs.

Oh how about 8Gohms capability?

The manual just states larger than 80 Mohm. Do they specify accuracy anywhere? Interesting how the accuracy for the lower resistance ranges (0.3% + 5 counts) is much worse than DCV accuracy (0.05 + 5 counts for most of the ranges). On good meters these figures are usually quite close.

[T4P]

"High frequency accessory" 
Yeah i noticed the "Plus Adapter thing" Got to try it another time. i'll play with it another time and figure out the multiplier ratios

Of course this isn't a good meter by any shot but if you live in a country like mine you will not find a HP 3468 so easily (not that you would) or you have to pay shipping which costs about roughly how much a new VC8145 costs seriously stop comparing
Still has better accuracy than a UT61E  and of course bench DMMs don't come cheap in fact most of them of the same spec are considerably more expensive at least
Similar accuracy with a BK 2831E and yet wytnucls likes to knock it so much

Maybe when i tear it down i'll see if there's any oscillator module inside if there is, i'll hack in a better one (Or if it's a crystal ... Is it possible to hack in a osc module?)
You know what i really needed? AutoHold, i badly needed autohold without buying a fluke (110 series costs something like 200+$ here)

[nctnico]

Yes, all you have here is a mediocre 30.00$ DMM PCB, hooked up to an 8.00$ transformer, placed in a huge plastic box, selling for 140.00$. Vichy must be laughing all the way to the bank with this one. 

You could bash it as much as you want. I have one and I'm really happy with it. I actually prefer it over my HP3466A because of its features. It's accuracy isn't worse or better than similar instruments like the ones from BK Instruments. Besides that you won't find much benchtop multimeters capable of handling 20A with a backlit LCD display. There are loads of used HP and Fluke benchtop meters for sale on Ebay but their crappy LCD displays are hard to read and they can only handle a few amps.

@T4P: maybe you could use the min/max function as auto-hold.

[T4P]

Hold goes into autohold automatically ... 

[Wytnucls]

Slow auto-ranging too, perhaps?
https://www.eevblog.com/forum/reviews/question-about-vc8145-newbie/msg164949/#msg164949

[alm]

Yes, the unbacklit displays that Fluke used and HP used during mid to late eighties are annoying. I find the 7-segment LED displays much nicer than backlit LCD displays, though, because of their viewing angle. I don't care about the increased power usage for a bench meter, and I can live without an alphanumeric display or graphics. The more recent bench meters tend to use VFD, which is also nice.

Even many current bench meters don't go beyond 3A. Not sure what this is about. Maybe they don't expect bench meters to be used with such high currents? Of course external shunts are much more convenient on the bench than in the field.

[T4P]

Slow auto-ranging too, perhaps?
https://www.eevblog.com/forum/reviews/question-about-vc8145-newbie/msg164949/#msg164949

You don't even own one and you just shoot off your mouth that it's slow in auto-ranging. It's speed is not bad and guess what? Several DMMs are much slower.

[Monkeh]

Slow auto-ranging too, perhaps?
https://www.eevblog.com/forum/reviews/question-about-vc8145-newbie/msg164949/#msg164949

You don't even own one and you just shoot off your mouth that it's slow in auto-ranging. It's speed is not bad and guess what? Several DMMs are much slower.

Oh my GOD! Somebody has criticisms of a device you own! KILL THEM! THEY'RE WRONG AND EVIL AND STUPID!

[Wytnucls]

No, if you had bothered to read the thread, you would have seen that it is a problem encountered by someone who actually owns the same bench meter as yours.
I don't shoot my mouth off as you say, unlike you, who badmouths a certain multimeter at every occasion, without ever having owned one.
It seems that you can't take your own medicine when it matters and Vichy/Uni-T 61E Kool-Aid doesn't impress me.

[Bored@Work]

You are falling into a typical trap. Because you bought one you feel the need to justify your purchase by all means. But that doesn't change the fact the thing is crap. All show, no substance. Pretty much looks like it is build around a garden variety multimeter IC put into a largely empty box to sell it for an inflated price. Just like the Uni-T 801, 803 and 804 lunch boxes.

Now, unlike Dave, I am a fan of bench multimeters. But that thing doesn't cut it. I would love to see a small, entry level, safe bench multimeter, build around a common multimeter IC and maybe $10 more expensive than a corresponding handheld. Because that would allow more people to see the advantage of a bench meter. But it has to be honest, not an empty lunch box bench multimeter poser.

[nctnico]

At what point do you feel the VC8145 doesn't cut it (*) and what would be your alternative?

Don't forget different people have different wishes. When I looked for a multimeter I wanted a big & easy readable display (preferably LED) so I can look where my probes are and peek at the display, >10A current handling capability and mains powered so I wouldn't have to change batteries all the time. With my demands the list of candidates got short real quick and interestingly the VC8145 was one of the very few that actually fit the bill. Most (99.9999%) handheld DMMs only have 3.5 digit resolution which is not enough for anything serious. Most benchtop DMMs are all about precision (which I don't need), have tiny displays and only a very limited current handling capability.

* Please skip the empty box argument. Every modern instrument is a mostly empty box.

[T4P]

No, if you bothered to read the thread, you would have seen that it is a problem encountered by someone who actually owns the same bench meter as yours.
I don't shoot my mouth off as you say, unlike you, who badmouths a certain multimeter at every occasion, without ever having owned one.
It seems that you can't take your own medicine when it matters and Vichy/Uni-T 61E Kool-Aid doesn't impress me.

I don't need to own a UT71 to say it's crap, like i said before i bought one and returned it in a week

[Wytnucls]

Keep your story straight, last time you said you borrowed one for a week. Maybe you just saw one in the shop window once. I rest my case.
And before that, you always referred to other people opinions, like Lightages, who does own a 71E, without any supporting evidence of your own. You've been caught in a lie.

[Bored@Work]

At what point do you feel the VC8145 doesn't cut it (*)

Please spare us this trolling attempts to waste others and my time. Every grown-up can check that on his own, and if you after that still think it is worth buying then by all means waste your money and buy one.

[nctnico]

At what point do you feel the VC8145 doesn't cut it (*)

Please spare us this trolling attempts to waste others and my time. Every grown-up can check that on his own, and if you after that still think it is worth buying then by all means waste your money and buy one.

Well if you think something is not worth buying then please enlighten others on what technical grounds you have formed your opinion (or just keep quiet). Its always good to have extra insights on what to look for when selecting equipment.

To sum this thread up to this point the only cons I can find is that the VC8145 is mostly an empty box, it is not as accurate as a high end multimeter which is more than 10 times expensive and that the VC8145 is not made by Fluke. All in all the negative comments are just FUD.

[david77]

@T4P and other owners of this meter:

Instead of bickering with others could you not just test the damn thing and give us a bit of a review & teardown on it?
Is it usable? Does it do what the maker claims? What's the buid quality like? And let's have a look at that board in there.
Does it really have that function gen in there and what can it do? The data on Vichy's site is a bit confusing, and it must be said Vichy's homepage is not impressive at all.

[alm]

To sum this thread up to this point the only cons I can find is that the VC8145 is mostly an empty box, it is not as accurate as a high end multimeter which is more than 10 times expensive and that the VC8145 is not made by Fluke.

Let's compare it to the much more expensive UT-61E:
- DCV, R are slightly better
- ACV is slightly better as long as you don't use the upper 25% of the ACV ranges
- DCA is better
- ACA has less bandwidth, especially in the amps ranges (50-500 Hz vs 45 Hz - 5 kHz)
- Capacitance has much less range, only up to 100 uF instead of 220 mF
- Frequency has worse lowest range and resolution (1 kHz vs 10 Hz) and accuracy (0.1 % vs 0.01 %), and the UT-61E claims to go to 220 MHz without extra gadgets. So much for the ten digits of resolution.

It's slightly better in some functions, but surprisingly worse than a hand held sold at half the price in others.

[grenert]

To sum this thread up to this point the only cons I can find is that the VC8145 is mostly an empty box

That's a pretty significant con, I think.  I don't want my equipment taking up 3-4X more space than it needs to.

* Please skip the empty box argument. Every modern instrument is a mostly empty box.

No, only junk instruments are mostly empty box.  Have you not seen teardowns here of:
Fluke 8846A bench DMM
https://www.eevblog.com/forum/reviews/fluke-8846a-teardown-9409/

HP/Agilent 34401A bench DMM
https://www.eevblog.com/forum/reviews/hp34401-teardown/

Agilent E3631A power supply
https://www.eevblog.com/forum/reviews/teardown-agilent-e3631a-power-supply-(picture-heavy)/

Agilent 33521A function generator
https://www.eevblog.com/forum/reviews/agilent-33521-teardown/

Fluke 196B portable oscilloscope
https://www.eevblog.com/forum/reviews/video-teardown-and-repair-of-a-fluke-196b-handheld-scopemeter/?nowap

And of course, Dave's teardowns of the Agilent DSOX and Tektronix MDO oscilloscopes.

It's not just really expensive stuff that is actually filled.  Look at this Rigol DM3058 bench multimeter
https://www.eevblog.com/forum/reviews/teardown-rigol-dm3058-(multimeter)/

These are not empty boxes.

On the other hand, the garbage Atten ATF20B function generator has quite a bit of air inside:
https://www.eevblog.com/forum/reviews/atten-atf20b-teardown/

[Rick]

To sum this thread up to this point the only cons I can find is that the VC8145 is mostly an empty box

That's a pretty significant con, I think.  I don't want my equipment taking up 3-4X more space than it needs to.

* Please skip the empty box argument. Every modern instrument is a mostly empty box.

No, only junk instruments are mostly empty box.  Have you not seen teardowns here of:
Fluke 8846A bench DMM
https://www.eevblog.com/forum/reviews/fluke-8846a-teardown-9409/

HP/Agilent 34401A bench DMM
https://www.eevblog.com/forum/reviews/hp34401-teardown/

Agilent E3631A power supply
https://www.eevblog.com/forum/reviews/teardown-agilent-e3631a-power-supply-(picture-heavy)/

Agilent 33521A function generator
https://www.eevblog.com/forum/reviews/agilent-33521-teardown/

Fluke 196B portable oscilloscope
https://www.eevblog.com/forum/reviews/video-teardown-and-repair-of-a-fluke-196b-handheld-scopemeter/?nowap

And of course, Dave's teardowns of the Agilent DSOX and Tektronix MDO oscilloscopes.

It's not just really expensive stuff that is actually filled.  Look at this Rigol DM3058 bench multimeter
https://www.eevblog.com/forum/reviews/teardown-rigol-dm3058-(multimeter)/

These are not empty boxes.

On the other hand, the garbage Atten ATF20B function generator has quite a bit of air inside:
https://www.eevblog.com/forum/reviews/atten-atf20b-teardown/

Could remind us the price of those new instruments you mention ?

[Simon]

Does this meter come from the same conmen that did the VC99 ? If it does I wish you luck, you will need it !

[grenert]

Could remind us the price of those new instruments you mention ?

The point is not that these are suggested as alternatives for the Vichy.  The point is that this $200 bench meter, and likely every new $200 bench meter is junk.  You just can't put together a good bench meter at this price.  What you can do at this price is put a mediocre handheld in an oversized case and power it off the wall, and that is what they did.  At the cost premium over what the handheld would cost, it doesn't make any sense.

[nctnico]

To sum this thread up to this point the only cons I can find is that the VC8145 is mostly an empty box

That's a pretty significant con, I think.  I don't want my equipment taking up 3-4X more space than it needs to.

The whole point of a bench DMM is that you can stack things on top! I have 2 bench DMMs and a power supply stacked on top of each other. In the end the 'empty' box is actually saving space. When using a handheld DMM I always had to put it upright against something in order to be able to read it but in the end it always was in the way.

[Rick]

Does this meter come from the same conmen that did the VC99 ? If it does I wish you luck, you will need it !

Regarding the VC99, I have recently received my second VC99 from China.
You will be amazed to hear what the Chinese seller told me. She said that she is selling plenty of that DMM. Selling very well actually. So for most people it is ok. But I shall not buy another Vichy because of its slowness.

[grenert]

The whole point of a bench DMM is that you can stack things on top! I have 2 bench DMMs and a power supply stacked on top of each other. In the end the 'empty' box is actually saving space. When using a handheld DMM I always had to put it upright against something in order to be able to read it but in the end it always was in the way.

Ha ha!  You have a very good point there.  Yes, I certainly take advantage of the stacking feature of bench equipment, probably more than is safe!  I agree that a bunch of handheld stuff on the bench does tend to get knocked around a lot.  A good tilt bail helps, but those seem to be harder to come by these days.

[T4P]

Does this meter come from the same conmen that did the VC99 ? If it does I wish you luck, you will need it !

Regarding the VC99, I have recently received my second VC99 from China.
You will be amazed to hear what the Chinese seller told me. She said that she is selling plenty of that DMM. Selling very well actually. So for most people it is ok. But I shall not buy another Vichy because of its slowness.

Simply not the same animal.

[nctnico]

Could remind us the price of those new instruments you mention ?

The point is not that these are suggested as alternatives for the Vichy.  The point is that this $200 bench meter, and likely every new $200 bench meter is junk.  You just can't put together a good bench meter at this price.

They used to say the same about Rigol scopes. The rest is history... Labour in China is cheap for both engineering and production. If you put a DMM into an ASIC which needs very few external components then you can mass produce something decent and sell it for a price low enough so lots of people can afford it.

[T4P]

Keep your story straight, last time you said you borrowed one for a week. Maybe you just saw one in the shop window once. I rest my case.
And before that, you always referred to other people opinions, like Lightages, who does own a 71E, without any supporting evidence of your own. You've been caught in a lie.

Troll much? What if i told the sequences happened one after another? Your pathetic attempt at trolling has been denied.
First earlier (June or September?) this year i bought a UT71A and felt it was utter rubbish, went out of cal within a week. so i returned it
Nevermind so later this year i borrowed a UT71E to see if it was any better (Being a different price point, something like 200$) but no it wasn't.
Still rubbish

[Wytnucls]

Yeah, right, whatever...my bullshit meter is glowing red. Wasn't helped by that tall ever changing tale about a Vichy 99 exploding in your hand, first without, then with glove. I think you're a phony and a first class distorter of the truth.

[T4P]

I'll let you think what i think, it doesn't change the fact that the UT71 is still a bad series.
And thus a troll is a troll.

[Wytnucls]

I'll let the reader decide who the troll is. The evidence is all here for everyone to see.
By the way, where is the VC8145 review? Did we put you off or are you incapable of doing a proper one?
Come to think of it, you never did one of the UT-71A and E models, that supposedly passed through your hands, either. Not even a picture, zip, nada, not a peep! Too busy posting inane comments in everybody else's thread, perhaps?. Nearly 4,000 posts and no reviews.
What is is with that post count of yours anyway? Are you trying to overtake Dave and Simon to gain some respectability, that you cannot achieve otherwise? It nearly gives a new meaning to quantity over quality.
I'm glad there is only one jerk on this site, otherwise it would become unbearable very fast.

[T4P]

Overtake? Don't make me laugh, boy. If there was a jerk right now it's you alright.
I really don't have time now to make a review as that requires some thinking and thought and i'm probably not posting here either

[EEVblog]

Guys, stop the slanging match now, or the thread gets locked.

Dave.

[Wytnucls]

I'm done. My apologies to Dave and others who are still reading this thread, but I had to get it off my chest.

[SeanB]

I bought a UT81B this weekend ( second owner) and am pretty happy with it. Nice little addition to the toolbox, and has come in useful already. Yes, has drawbacks, but I am still learning how to use it and what it's capabilities are, but so far very nice and usable. Nice big display in meter mode is a nice plus for viewing, and I did use the hold mode in scope mode already as I ran out of hands and used a pinkie to press the hold while holding probes in the circuit in question.

[nctnico]

I'll try to take a stab at a review:

I think I already made clear in this thread what I want from a bench multimeter so I won't go into that again. The VC8145 offers many features besides just measuring volt, current and resistance. It can measure capacitors, frequency, RPM,  duty cycle, diodes and temperature. As an extra bonus it is also capable of generating a square wave with adjustable duty cycle. The frequency of the square wave is selectable from 16 frequencies between 0.5Hz and 5kHz.

It has a dual display so it can display two values at once. At the bottom of the screen there is a bar-graph which gives a quick indication of the measured value. For instance it can display both DC and AC components in the volt and current modes but also the frequency when selected. The 2nd view button controls what is in the secondary display at the right top of the screen. In temperature mode it shows both Celcius and Farenheit. There is something odd about the temperature mode though. When pressing the 'TEMP' button it apparantly shows its internal temperature (which is supposed to be the room temperature). You need to press 'select' for the meter to use the external temperature probe. This tricked me into thinking the temperature probe that came with the meter was broken.

When measuring AC it can also display the values in dBm with a large selection of reference resistances ranging from 4 Ohm to 1200 Ohm including 50 Ohm, 75 Ohm and 600 Ohm which are often used.  Other neat features include auto-hold and positive and negative peak hold. Most advertisements say the meter has an isolated serial port but you actually need an extra adapter which provides the isolation and RS232 interface. Talking about adapters.. the input bushes are spaced according to the 'standard' distance so they accept a 4mm 'banana' plug to BNC adapter.

Overall the designers of the VC8145 did their best to pack as many usefull en less usefull features they could think of into an affordable bench multimeter. I think they came up with a very complete product. I always like equipment where the engineers clearly got some say in the product specifications.

I own the VC8145 for over a year now and I must say I don't regret buying it. It has become my preferred DMM. It defaults to autoranging but the autoranging is not as slow like on some hand-held meters. The autoranging works faster than having to press a range button. The casing doesn't have rubber feet so it tends to slip away. Some stick-on feet solved that problem. Furthermore the meter likes to beep a lot. It beeps when it is switched on, when you press a button and when it needs to make a big switch in range. The probes that come along with it are just standard el-cheapo probes. I use these probes which are much better for probing around in SMT circuits:
http://uk.farnell.com/hirschmann-test-measurement/pms0-64-smd/test-kit-micro-60v/dp/1011414

[Rick]

I bought a UT81B this weekend ( second owner) and am pretty happy with it. Nice little addition to the toolbox, and has come in useful already. Yes, has drawbacks, but I am still learning how to use it and what it's capabilities are, but so far very nice and usable. Nice big display in meter mode is a nice plus for viewing, and I did use the hold mode in scope mode already as I ran out of hands and used a pinkie to press the hold while holding probes in the circuit in question.

Can you plug it into the wall socket and visualize the mains voltage in the oscilloscope mode?

[SeanB]

Why would I want to do that? I have a perfectly good set of other CAT3 meters to do that with.

[Rick]

To visualize the waveform for example. Somebody was talking a few days ago about sending a modulated carrier through the mains. I have in the past done a small such project. In which case if you want to inspect what is being sent to the other side of the transformer, it would be very useful, wouldn't it, see the amplitude etc.
If you pay an extra $60, you can get the cheapest UNI-T which has a better screen I believe. But somebody was saying one channel handheld scopes are useless...  the 2 channel ones cost at least $500. What is your opinion?

[SeanB]

If I do that I will use an external 10X capacitive divider to drop the voltage, as it will be safer for me to work with. In most cases i will be using it for low voltage work, where it has good utility. May be rated to 1000V but I still need to check the calibration, it overreads by 1 digit on 10V, showing 10.01V and is quite linear about it, 20V shows 20.02V

[T4P]

The probes that come along with it are just standard el-cheapo probes. I use these probes which are much better for probing around in SMT circuits:
http://uk.farnell.com/hirschmann-test-measurement/pms0-64-smd/test-kit-micro-60v/dp/1011414

Yeah, the probes are pretty crappy. I think i mentioned this but again i might have forgot, i had some probes i got for about 5~6SGD that are miles better than the probes supplied. Not a problem, i'll always throw crappy probes into the bin

[iloveelectronics]

I usually keep the leads just so I have some spare thick-ish wires to use for some projects

The probes that come along with it are just standard el-cheapo probes. I use these probes which are much better for probing around in SMT circuits:
http://uk.farnell.com/hirschmann-test-measurement/pms0-64-smd/test-kit-micro-60v/dp/1011414

Yeah, the probes are pretty crappy. I think i mentioned this but again i might have forgot, i had some probes i got for about 5~6SGD that are miles better than the probes supplied. Not a problem, i'll always throw crappy probes into the bin

[T4P]

I usually keep the leads just so I have some spare thick-ish wires to use for some projects

The probes that come along with it are just standard el-cheapo probes. I use these probes which are much better for probing around in SMT circuits:
http://uk.farnell.com/hirschmann-test-measurement/pms0-64-smd/test-kit-micro-60v/dp/1011414

Yeah, the probes are pretty crappy. I think i mentioned this but again i might have forgot, i had some probes i got for about 5~6SGD that are miles better than the probes supplied. Not a problem, i'll always throw crappy probes into the bin

Actually that's what i do  But damn, 1 star rating -facepalm- It's all thanks to wytnucls for derailing the thread

[Wytnucls]

The truth does bother you quite a bit, doesn't it?
Let's see who derailed the thread, with personal attacks:

[Wytnucls]

Dave or Simon, please lock this thread, there is nothing to see here. We're not going to get an impartial review of this meter anyway. 

[Monkeh]

The truth does bother you quite a bit, doesn't it?
Let's see who derailed the thread, with personal attacks:

Personal attacks? Okay, we clearly have a very different definition of personal attack.

[ales22]

This thread is pointless from 2nd post, where all can see that this meter (and all cheap benchtops, Uni-T incl.) is handheld guts put in large plastic box with mains transformer. This fact implies all cons and pros discussed here. Someone finds all cons negligible and is very happy with that meter, someone won't buy just for only one reason. That's my case too, because my workbench is 0.6x0.9 meter, I can't waste space with fresh air packed in plastic box. I would go for handheld. But it doesn't mean that this meter is not good. It's not good for me.

[Rick]

There are 5 1/2 digit bench multimeters out there on ebay, for example the much praised HP 3478A for $150, I would buy one of those rather than the VC8145.
Of course you need to find the right seller (there are some) who has the device you want and not the crook who tries to pass his faulty device off on you as a good one ( I tried this verb for the first time I hope it is ok). Hey at least I improve (or I have the impression that I improve) my English here
Seriously having seen other people trying to repair their stuff is really dissuasive for us abroad. You pay lots of money for shipping and the guy sells you a crappy multimeter. You have to pay about the same amount to return it to USA. This is too much to bear.

[nctnico]

What multimeter you buy is up to you. All I'm saying is that people should give an unknown brand a try. Chances are that equipment for Tektronix, Agilent, Lecroy, etc is rolling of the same production line or designed by the same people. Anyway, I've taken some pictures of the inside of my VC8145:
The rear with the 'RS232' interface, power supply and transformer


The front:


A close-up of the inputs. I like the inputs bushes are not soldered onto the PCB but use screws (with a spring washer). Soldered bushes often give problems in the long run.


An overview of the display board with a Holtec 8 bit microcontroller and what seems to be a display controller:


The 'RS232' plug on the back seems to be isolated after all.


Here is the analog board without the shielding:


On the analog board there are several hybrid resistor ladders, a special chip and some regular stuff like an LM385 1% reference and a 12bit DAC. The DAC is interesting because it is relatively expensive costing more than $5 even when bought in large quantities. The designers clearly didn't cut a corner here.


Furthermore there are some relays from Omron and two HC4053 analog muxes from ST


Edit: moved pictures to Flickr

[nctnico]

Seriously having seen other people trying to repair their stuff is really dissuasive for us abroad. You pay lots of money for shipping and the guy sells you a crappy multimeter. You have to pay about the same amount to return it to USA. This is too much to bear.

Buying second hand test equipment is a bit of an art. If you want to buy something you need to check for known problems on forums like these. Also be sure to check the feedback when buying from Ebay. Actually most sellers from the US don't try to sell you crap because they don't want the fuss. If they don't know how to test it they are honest enough to sell it 'for parts'. Asians OTOH are very prone to sell bad used equipment. The prices usually are very reasonable but expect some hidden surprises!

[Rick]

Ok thanks for the good advice.
Right, especially stuff from a few sellers from Singapore seem dodgy to me, I don't know...
And when you buy from China it's better to buy new equipment of course.
Shall you make some measurements with that VC8145?
We don't have the possibility to go and pick up stuff ourselves like T4P, so... and shipping old stuff from Singapore and China is as expensive as shipping from USA.
Recently I have discovered that shipping by sea from Australia is very interesting but it takes up to 3 months for the items to arrive...
Actually I am fairly sure some sellers from USA know well their devices are no good but prefer to stay on the safe side by saying "for parts or repair" just in case the buyer would complain to ebay.
Generally speaking if the seller does not answer specific questions, it is better not to buy. People who don't know how to run basic tests should not be allowed to sell such items.
You say "could you please measure the voltage of a 9V battery, a resistance and the mains voltage" and you hit a wall of silence.
Obviously there is something wrong out there:)
On the other hand you have US sellers who make videos of the self test sessions or provide the pics of measurements. These are the rare good ones. I missed the opportunity to buy a Fluke 8840a from such a guy. It was quite cheap.
I mean generally buying on internet is a risk, we cannot accuse specifically US sellers, I talk about them because Fluke instruments are mainy sold in USA. We have plenty of crooks here on our local equivalent of ebay. If you are lucky you buy from the good guy but the others hide the faults of their devices.

[grenert]

On the analog board there are several hybrid resistor ladders, a special chip and some regular stuff like an LM385 1% reference and a 12bit DAC. The DAC is interesting because it is relatively expensive costing more than $5 even when bought in large quantities. The designers clearly didn't cut a corner here.

What is the DAC chip you see, and what is the multimeter doing with the DAC?

[rsjsouza]

I've taken some pictures of the inside of my VC8145:

Thank you for the time to put both the information and the pictures together... Plowing through the noise I really enjoyed finally seeing some info related to the actual equipment. 

What is the DAC chip you see, and what is the multimeter doing with the DAC?

I guess it is the SOIC-8 AD739J device. Maybe I am misreading the part marking, but I could not find an AD739, but instead an AD7390 (12-bit) or an AD7391 (10-bit) with the same package...

[Monkeh]

What is the DAC chip you see, and what is the multimeter doing with the DAC?

I guess it is the SOIC-8 AD739J device. Maybe I am misreading the part marking, but I could not find an AD739, but instead an AD7390 (12-bit) or an AD7391 (10-bit) with the same package...

No, that's an AD737J.

[rsjsouza]

No, that's an AD737J.

You are probably right, but oh boy, I must be getting blind...  I still can't see a seven there, but per the device description (TRMS-DC converter) it surely pertains to a DMM. Thanks!

[Monkeh]

No, that's an AD737J.

You are probably right, but oh boy, I must be getting blind...  I still can't see a seven there, but per the device description (TRMS-DC converter) it surely pertains to a DMM. Thanks!

Your eyes are fine, it's just a terrible picture of a dirty IC. More megapixels does not mean you can skimp on good optics.

[rsjsouza]

Your eyes are fine, it's just a terrible picture of a dirty IC. More megapixels does not mean you can skimp on good optics.

this is our current world of built-in cameras...

[nctnico]

I've used a Canon camera not some cheap-ass camera from a mobile phone. The part number is really hard to read even using a 5x magnifier lamp. Actually the picture is more legible than when using the magnifier lamp! The AD737 makes sense. The quality of the part number stamp is really poor.

[rsjsouza]

I see then... The part markings may be etched (they are very hard to read unless lighting hits them at a specific angle). Thanks anyways.

[T4P]

Finally had time to do a teardown/review. I wrote all night for this one 
http://the4thpin.comeze.com/2013/01/21/vc8145-review-finally-about-time-i-guess/

[alm]

RS-232 is isolated, but the transformer only has one secondary winding as far as I see. How is the PC side of the opto-coupler powered? Is there a TTL to RS-232 level converter after the opto-coupler? If these are powered by the handshaking lines, you might run into trouble with some USB-RS232 converters. I know Fluke made an RS-232 to IR cable which only worked with a limited set of USB-RS232 converters. I wonder if their 'special adapter' has something to do with this.

The ground pins of the RS-232 connector should be connected to earth ground, curious that they chose to omit any ground connection.

4 readings/sec for the digits and 40 readings/sec is pretty much standard for any decent handheld DMM I've handled. The '30 year old tech' bench meters will do much more, especially in 4.5 digit mode.

[nctnico]

I just did some testing and I could use the PC control software by connecting a standard RS232 cable to the back of the VC8145. So it seems the optocouplers are getting powered by the computer's RS232 interface. I have used similar tricks in my own designs when RS232 was common.

[T4P]

4 readings/sec for the digits and 40 readings/sec is pretty much standard for any decent handheld DMM I've handled. The '30 year old tech' bench meters will do much more, especially in 4.5 digit mode.

Yeah when they have like nominal 5.5d mode. Please. I can't get any of those meters for under 300$ (If shipping from US, it's a bomb) if i wanted to. PLEASE!
"Decent handheld DMM" In context i am speaking of 150$ brand new DMMs with 80000 count resolution. Not that you can find any.
MS8218? 2 rdgs/sec
UT71D? 2 rdgs/sec

I just did some testing and I could use the PC control software by connecting a standard RS232 cable to the back of the VC8145. So it seems the optocouplers are getting powered by the computer's RS232 interface. I have used similar tricks in my own designs when RS232 was common.

In the same way the UT61E's RS232 works i guess 

[Wartex]

Guys, stop the slanging match now, or the thread gets locked.

Dave.

Slanging means having a huge dick. You mean "slandering", perhaps?

[elcomtel]

For what this bench multimeter is intended for I think this is a fine meter. As far as the criticism regarding the free space inside, Aka 'lunchbox'.

This cavernous space opens ups some possibilities for custom expansion. Think of the possibilities and what you could use that space for. There are lots of kits on the market that are expected to be used in conjunction with a multimeter. Now you have the perfect multimeter that you can easily modify.

[SeanB]

Best use of the space is to remove the mains transformer and replace it with a 16VAC 1A unit with an interwinding shield, and put in a 4AH SLA battery and charger in there. That way you have a power supply that is both mains and transportable. Connect the mains ground to the RS232 shell and the screen winding on the transformer to it. Add in a mains common mode filter with an earth choke and some transient suppression as well, so as to reduce conducted noise from interfering with your high resolution measurements.

Otherwise you could put in a small microcontroller board with a SD card slot ( Rasberry Pi)and have a nice datalogger with a very large sample memory and the ability to do long term logging. woul probably need a battery as well and so use a 2AH SLA instead and build a switching 8V regulator for the multimeter itself to reduce power drawn from the battery when mains fails.

[Uwe Hermann]

Just some additional info: The review page at http://the4thpin.comeze.com/archives/1260 says "Fortune FSuP01-003, couldn’t find that on the web ANYWHERE".

The company is Fortune Semiconductor, http://www.ic-fortune.com/. Can't find a datasheet for the specific chip atm, but the FS970X datasheet at least mentions it under "typical application circuit" and shows the pinout.

http://www.ic-fortune.com/upload/Download/FS970X-DS-42_EN.pdf

Uwe.

[silicon junkie]

Anyone had any luck getting the RS232 to work on the VC8145 multimeter?
I have the opto-coupler powered & wired correctly but just don't get any data out.
I have also tried sticking a scope directly on the PCB where it drives the opto-coupler and can't see any data at all
(Yes i have enabled the RS232 by pressing the 'timer' button for two seconds)
Thanks

[nctnico]

I managed to get it working. AFAIK you must NOT press the timer button; RS232 is on by default.

[gljoshhunsaker]

Hi,

I wanted to put another post in on this topic (I don't see many other threads online that have any info about this piece).  I picked one of these guys up and have been very impressed so far.  My cheap Innova 3320 handheld meter was not able to do a current draw measurement of any kind on a particular product sample that I have been testing, but the VC8145 worked a treat.  Provided what appeared to be very reliable (in terms of matching what was stated from my company's manufacturer) current draw measurements so far.  The backlit display is lovely.  The quaint little built in function generator option is kind of cool! (I still need to verify it against my rubidium standard calibrated frequency counter, but neat regardless).

I have noticed the mA readings don't zero when nothing is hooked up (floats between about +2 - 4 microamps), does anyone know of a way to internally calibrate this unit for that kind of thing?  Not a huge deal, but otherwise this is pretty decent really.

[lupine]

SB, thanks I like that Idea I was actually thinking the bigger LiPo battery in side and a"PiTop" that connects to this meter for power and to the data port of the meter with appropriate sized screen and room for connectors for using a BitScopeMicro as a sort of sub $400 all one mobile digital test lab...any thoughts ... in the meantime the 20A fuse will keep me from blowing it up on slot car projects (7.5 - 16VDC & 3 to 16 amps) and the 36 hour logging ability will allow me to track the power usage for my current battery powered projects (semi portable clock radio's that only need 24 or so hrs of UPS) without cranking up a computer... unless I find better bang for the buck this is the one I'm gonna order one when the paycheck comes around. more l8r

Best use of the space is to remove the mains transformer and replace it with a 16VAC 1A unit with an interwinding shield, and put in a 4AH SLA battery and charger in there. That way you have a power supply that is both mains and transportable. Connect the mains ground to the RS232 shell and the screen winding on the transformer to it. Add in a mains common mode filter with an earth choke and some transient suppression as well, so as to reduce conducted noise from interfering with your high resolution measurements.

Otherwise you could put in a small microcontroller board with a SD card slot ( Rasberry Pi)and have a nice datalogger with a very large sample memory and the ability to do long term logging. woul probably need a battery as well and so use a 2AH SLA instead and build a switching 8V regulator for the multimeter itself to reduce power drawn from the battery when mains fails.

[Hydrawerk]

Finally had time to do a teardown/review. I wrote all night for this one 
http://the4thpin.comeze.com/2013/01/21/vc8145-review-finally-about-time-i-guess/

That link does not work anymore.

[mstck]

I just received one of these and I am now getting to know it. I have a question about the default start up.  The unit I have starts with RS232  enabled and auto power off (APO) disabled. To turn on APO I have to press the Timer/RS232 button. Is this the default position others observe?

[nctnico]

Why would you want auto power off? The transformer uses more energy due to losses than the rest of the meter.

[Macbeth]

Why would you want auto power off? The transformer uses more energy due to losses than the rest of the meter.

I've always hated APO even on my battery powered meters. Why subject yourself to that shit when you have a bench meter, even if it is a bit of a joke meter?
(The least hey could have done with all that wasted space was have a little cabinet to keep all your probes and sensors in?? - I could go along with that)

[nctnico]

A bench meter usually is 99% empty space. My HP3466A is the same. It's a bit weird to comment on a box being empty because there is more or less a minimum volume requirement for a bench meter 

[Macbeth]

A bench meter usually is 99% empty space. My HP3466A is the same. It's a bit weird to comment on a box being empty because there is more or less a minimum volume requirement for a bench meter 

Not at all - all the latest DSO's are compact and bijou. Why can't bench meters, specifically ones that don't have anything in them, not follow the same form?

Your HP3466 has a large circuit board and no doubt cooling requirements. The same can't be said for the VC8145. It loses all credibility.

[nctnico]

No, the HP3466 is just as compact (no cooling requirements) and empty as a VC8145. The reason for the minimum volume requirement is that bench equipment typically gets stacked. So if they all have the about the same size you can make a neat stack. I have 2 VC8145 and a bench power supply stacked on top of eachother. Before that the HP3466 was in that stack. If the VC8145 was much smaller it could not be stacked and would clutter the desk space.

[Wytnucls]

I don't think you could make the HP3466 much smaller, unlike the VC8145:

[nctnico]

Still there is plenty of empty space in the HP3466 if you look from the side. They could have made it a lot smaller but they didn't because the designers could fill the entire box if they wanted. I see a lot of green on the circuit board which means a lot of board space is not used / the components are spread widely over the board. They could have cut the height in half easely.

Again: a bench multimeter is supposed to have a certain size and the VC8145 fullfils that requirement. By making it smaller it would be useless as a bench multimeter because you can't stack them properly. If you want a small multimeter you have to buy a portable one; the VC8145 is not for you.

[k2teknik]

Anyone had any luck getting the RS232 to work on the VC8145 multimeter?

Yes with the sw that is on the cd supplied with the instrument, I think it is a tow-way protocol so one may have to start talking correctly to the thing to make RS232 work.
There is a bug in the sw,you have to set you PC not to use comma as decimal point otherwise you will get a lot of errors.
The sw is most likely made for an other instrument and I am missing a useful guide for this.

Do any know about the sw protocol for this instrument?

[MarkPalmer]

You could always secure a lead ingot in that empty space in the VC8145 to keep the little fella from sliding around     Beckman bench meters from the 80's were sort of the same way- except you could load D batteries in the empty space to make them portable.   

HP bench meters of the past, like other HP test gear, went in to a system of standardized case sizes called, "Clement cases."  Whichever one fit the circuitry and overall design the best is the one that got used, so sometimes there was some internal space unaccounted for.  But with this system they didn't have to come up with a new case for every single instrument. 

-Mark-

[TunerSandwich]

they really should have considered better thermal management.....with that case packed so tightly, a fan would have been smart.....   Maybe you could "hack it" and add a full water cooling loop and some peltier.....be safe

[TunerSandwich]

. Now you have the perfect multimeter that you can easily modify.

 

[Dave92F1]

Does anybody know if the VC8145 is the same as the Unisource DM1105B?

See http://www.testequipmentdepot.com/unisource/multimeter/dm1150b.htm

I can only find two or three places online that sell the DM1105B, and they all charge about double what the Vichy (now "Vici" VC8145) goes for.

The two units look pretty much identical, and seem to have identical specs.  Either it's the same unit rebranded, or one is a pretty exact clone of the other.

I suspect the former (rebranded Vici).

[nctnico]

That DM1105B looks exactly like the VC8145 and the specs are also identical. I think the DM1105B is an expensive rebadge.

[Dave92F1]

I couldn't decide between the Rigol DM3058E and the Siglent SDM3055.  I wanted the sexy color screen of the Siglent, but the quality and reputation that goes with the Rigol.

So, after much indecision, I decided to save $300 and ordered a Vici VC8145. 

I'm not expecting it to match a $450 meter in terms of build quality or features (in fact, it looks a bit junky), but it will stack on my bench, has serial output for data logging, and a nice big readable display. If it basically works to spec, I'll be happy.

I'll post a review once I've had time to play with it (ordered from China, so it'll be a few weeks until it gets here).

[Macbeth]

I couldn't decide between the Rigol DM3058E and the Siglent SDM3055.  I wanted the sexy color screen of the Siglent, but the quality and reputation that goes with the Rigol.

So, after much indecision, I decided to save $300 and ordered a Vici VC8145. 

I'm sure it will be fine. In fact I am warming to it as I would modify it by adding a re-chargeable lithium battery, a $4 HC06 transceiver, and finally cut the case down to size for portability and saving bench space.

A nice portable 4 _7/8 digit bench DMM with bluetooth datalogging to my phone, laptop, PC... for only £110 ish, hmm... 

[gfiber]

I have owned a VC 8145 for some 5 or 6 years now. It is not labeled Vici however. It seems to be accurate though I have not tried every function on it. You will want some nice rubber feet on the bottom as it slides all over when pressing the buttons to change settings. I do not like the 'stand" or handle as it makes the face set up to high if on the top shelf of the bench riser. The beeps well they will wake you up. Otherwise for everything I measured it agreed with my old Fluke 77. I need to try the RS-232 output on the thing.

I am replacing the VC8145 with a Rigol 3058E and a recently acquired a Keithley 175A, though I need to replace the lighting strip in the Keithley as it s pretty dim.

[Dave92F1]

I'm sure it will be fine. In fact I am warming to it as I would modify it by adding a re-chargeable lithium battery, a $4 HC06 transceiver, and finally cut the case down to size for portability and saving bench space.

A nice portable 4 _7/8 digit bench DMM with bluetooth datalogging to my phone, laptop, PC... for only £110 ish, hmm... 

I was thinking much the same. Somehow I never have enough DMMs around, so someday I'll upgrade to a better one (probably the successor to the Rigol DM3058E, whenever they get around to that...) and the VC8145 will be a nice spare meter for various uses then.

[Dave92F1]

I have owned a VC 8145 for some 5 or 6 years now. It is not labeled Vici however.

According to http://www.vicimeter.com/en/newshow.asp?sendid=117 they changed their name from "VICHY" to "Vici" in April 2014. Probably somebody told them they'd spelled the Latin "vici" ("I see") wrong... Chinese can be amazingly casual about spelling of Western words. I suspect "Rigol" was meant to be "Rigel" (the star).

Do you know how to calibrate it?  From the photos there seem to be 4 trimpots (or trimcaps) in the VC8145.  I was thinking of contacting the Vici company in China and asking directly.

(Still waiting for mine to show up.)

[gfiber]

No I don't know how to calibrate it. The manual is small both in size and print. I need to blow it up a bit though it is in PDF format.

I just looked at my VC8145, no manufacturer name imprinted on it at all, not sure if it is a Vichy though I think it is as I bought it from Ebay. Never had any trouble with it, never even opened it up. I see the bottom has 8 screws two on each foot can't imagine it takes that many to hold the case together. The power connection and RS-232 ports are all screw mounted not snap on.
 
Once I get done with with my bench revamp I will play with this meter a bit to see what it does. Just used it for voltage readings in the past, though I liked it having a db capability.

[Dave92F1]

FWIW, mine has arrived and I unpacked it today and played with it a bit.

For $150, it's a very good meter.  It's not a $450 meter, tho (of course), let alone a $1100 Agilent.

Big, bright, easily readable display.

It does beep a lot needlessly, but I don't find it too annoying. The continuity check is not latching, but it's fast and loud - good enough for me.

I checked accuracy against a Doug Malone DMMCheck, a Fluke 876B, and a 40 year old 5.5 digit Systron Donner 7205 meter (in reasonably good calibration).

It's accurate - clearly within the stated specs (but not perfect of course). Not as accurate as the Systron Donner, but a digit more than the Fluke and always in agreement +/- 1 count (of the Fluke). In particular in most modes I notice it doesn't read zero even if you short the leads (it reads up to 5 counts away from zero). Not a big deal, and probably normal for a 80,000 count meter in this price range.

But it would be nice to figure out which trimpot adjusts the zero reading.      (But it has the relative measurement function, so you can do it manually if you really want.)

The backlight doesn't come on by default (for no reason, considering it's AC powered), and it doesn't remember that it was turned on the next time you power it up.

On the other hand, if I hold down the backlight button on power up, and keep it held down, it boots OK, backlight goes on, and everything works. So I could just short the button closed if I really wanted - not sure if it bothers me enough to do it yet.

I haven't tried the RS-232 output yet; tomorrow, probably.

Anybody who wants to know anything about it, just ask.

[Dave92F1]

Oh - another small annoyance. The LCD contrast is setup so that it's clear when looking at the meter from ABOVE - it's kind of washed out when viewing from the same height or below.

Which makes little sense for a bench meter, usually they go on the top shelf.

[Lightages]

I was looking for a bench meter just for the convenience. I considered the VC8145 but decided that a used Keithley 197 was much better value. I have one on the way. Why?

I have a a counter made by Victor and I am not impressed with the build quality. It works but I would rather have something used with a very good reputation even if I lose the data connection. The VC8145 is not going to match the build of the 197.

[Dave92F1]

The VC8145 we're talking about is made by Vici (used to be "Vichy"), not Victor.  Altho Victor does make a model 8145 - that's a totally different unit.

[Lightages]

Yes, I realize the difference in the manufacturer, but Victor seems to be better built than Vici!

[Dave92F1]

From the photos and manuals I've seen, I agree - the Victor build quality is better than the Vici.

But I wanted RS-232 output in a bench meter with good accuracy & resolution, and the Vici delivers that at a good price.  But I'll agree the build quality is lousy and this meter probably won't be around 20 years from now.

FWIW, I emailed the Vici company today asking about the contrast adjustment and calibration. If I get any reply at all (I don't really expect one), I'll post here.

I just finished hacking the backlight on the Vici make it come on at power up.  Just one jumper:

[Dave92F1]

I've had a chance to play with the RS-232 output a little.

The software supplied with the unit is beyond horrible. It doesn't run on x64 versions of Windows at all - 32 bit only. And it's really, really clunky.

It's 9600 baud; I haven't puzzled out the protocol yet. I'm looking to see if one of the (many) open-source DMM reading programs will work...

The RS-232 optocoupler is powered by the RTS line from the terminal (PC).  If your USB-RS-232 hardware/software doesn't raise RTS, it won't work.  It's working with RTS at +12 volts (per the RS-232 spec), but some USB/serial adapters only supply +5 or so; I don't know (yet) if that'll work.

[nctnico]

Which software included with a test instrument isn't horrible? They all are whether they come from an A-brand or a small Chinese brand! The software is there to show the communication works; it's up to you to tie it into your automated test environment.

[Dave92F1]

Which software included with a test instrument isn't horrible?

I've only seen software from Chinese suppliers - V&A (DMM), Uni-T (DMM), Rigol (oscilloscopes). And yes, they are all horrible. (I'd like to think that somebody out there offers software that isn't horrible, but maybe not.)

That's not a huge problem if the protocol is documented so you can write your own software. As far as I can tell, the VC8145 protocol isn't documented anywhere.

Poking around a little, it seems that if I interrupt the data stream from the PC to the VC8145, the DMM often crashes in some semi-spectacular way (beeps, crazy stuff on the display).  Not good, but a full power cycle does fix it OK.

On the plus side, I discovered that way that in principle it should be possible to adjust the display contrast - once when it crashed I got crazy random illuminated segments - but with excellent contrast from below...  :-)

I still think that it's a good value for the price. But some of these things would be trivial to fix at basically no cost. (Like releasing the protocol, calibration, and contrast adjustment details...even in Chinese would be fine - Google offers good-enough translation.)

[Dave92F1]

Today I did a little accuracy check comparing the VC8145 to my other DMMs and a recently calibrated (< 1 month ago) DMMCheck.

Here is error in the range +2%/-1% of reading:



and, zooming in on +/- 0.3% of reading:



This should be taken with a few grains of salt:

• This is one test on one date of one sample of each instrument.
• I haven't checked all modes or ranges - just these few.
• The SD7805 and UT61E were calibrated in the last year. The others are at the original factory calibration.
• The VA18B shows 3 1/2 digits, the Fluke and Uni-T show 4 1/2 digits. So the "dead-on" results in some cases just means it's correct to the LSD; a meter with more resolution may show a bigger error while actually being more accurate.

The VC8145 seems to be out of spec on the 1 mA test - it's off by about 0.7% (spec is 0.5% + 10 counts). Other than that it's within spec.

Of these 5 meters, the VC8145 has by far the best user interface - it's fast and convenient to use.  The SD7205 is the only other bench meter here - it's really accurate but otherwise outclassed in every way, it has very little in the way of features - not even autoranging.

[Mayor C]

It seemed to fit the  bill for what I wanted out of a meter and I must say I am very happy with it. I was using handhelds and was getting very POed with them falling over and turning as I was using them. I am not building space shuttles so I don't need anything super accurate and I won't be wearing anything out. Generally as I am working I use a magnifying glass to look through, the meters were always a look around, I put the Vici on a shelf and the large display is easy to see as I glance up. The other comments of it needing rubber feet are right on the money and I added them to mine. I may buy another and try to get all the handhelds off my bench, the dual display gets rid of two at a time.

I must admit, this is just a hobby to me, I usually build stupid little circuits, solder them together and throw them in the trash after I get them working. Other than the odd Arduino project I don't keep anything I make.

[k2teknik]

The chip (set) used is FS9704b http://www.ic-fortune.com/upload/Download/FS970X-DS-44_EN.pdf
This chip is not listed on http://sigrok.org/wiki/Multimeter_ICs
My instrument use 9600,8,N,1, have to use HW handshake to make communication work (ref voltage to signal, no communication on handshake signals)
It looks to me that the RS232 communication is done by the FSuP01 chip, I can't find info on that beast.

I had attach two files with loggin af communication, one Rx and one Tx, I may have tell that these file in byte format, so no sence to try to "read" them with Notepad etc.

Just added two more pictures, one of the UP board, remark the mode selector option, the second pic is the FS9704b chip, remark the apperently 8k/80k "thing".

Added 21-04-2015: This link http://xuewen.cnki.net/ArticleCatalog.aspx?filename=1012380427.nh&dbtype=CMFD&dbname=CMFD2012 maybe hold interisting info on the chipset (FS9704 + FS?P01), but I can't read Chinese or even make an acount to download the thing 
The SW for UNI-T UT70C works with the VC8145, except that the decimal point is in wrong position (Uni-t UT70C is 8000 counts, VC8145 is 80000 count).

Added 26-04-2015: Link to the Holtek HT48R30A data http://www.holtek.com/english/literature/IO_hb_3rd.pdf

[dev26]

Here are results of my reverse engineering attempt of the RS232 protocol: http://www.26th.net/blog/vichy-vici-vc8145-digital-multimeter-rs232-protocol/

[Lightages]

One thing I noticed in the manual is that the ACV accuracy is beyond terrible for values > 75% of each range: 8% of reading + 50 digits. Also note that ACV is only specified for frequencies >= 50 Hz.

As alm pointed out a long time ago, the AC measurement accuracy is horrible, worse than a joke. How do you guys reconcile that. Any handheld multimeter in this price range has much better specs.

[nctnico]

Utter nonsense. The ACV range is limited. If you stay within 75% of the range and between 50Hz and 20kHz it's accuracy is 0.8% of the reading +/-50digits. This is better than my (4.5 digit) Agilent U1241B handheld DMM which already is at 2% at 2kHz. At least Vici took the effort to characterise their meter properly so you have some clue what the readings outside the specs are worth.

You try to write bad things about the VC8145 every time. This time about a post from 2012. Why did you dig that up, quoted the wrong specs and say it is a joke without any technical merit? I know you import multimeters into South America. Why don't you start selling the VC8145 over there as well? Or is your competitor killing you with it?

[Lightages]

Utter nonsense. The ACV range is limited. If you stay within 75% of the range and between 50Hz and 20kHz it's accuracy is 0.8% of the reading +/-50digits. This is better than my (4.5 digit) Agilent U1241B handheld DMM which already is at 2% at 2kHz. At least Vici took the effort to characterise their meter properly so you have some clue what the readings outside the specs are worth.

I don't think it is nonsense what alm pointed out. How is 8% accuracy considered good if you exceed 75% of a range? 50 counts out at any reading? I have a handheld meter here that costs just a bit more and has  better specs IMHO. It is a matter of opinion because the specs are stated differently. 50-60Hz; 0.5%+3D, 40-500Hz; <600mV 0.8%+4D, <100V 1%+4D, <1000V 2%+4D, etc, and never worse than 3%+4D up to 3kHz.

You try to write bad things about the VC8145 every time. This time about a post from 2012. Why did you dig that up, quoted the wrong specs and say it is a joke without any technical merit? I know you import multimeters into South America. Why don't you start selling the VC8145 over there as well? Or is your competitor killing you with it?

Actually, in spite of your vitriol, I have considered buying one of these many times. Investigation has stopped me each time. When did I misquote specs? You are saying that alm quoted was a lie? If so, please show how the specs provided by Vici contradict his statements. I think I stand on my assessment based on the technical merit as stated by Vici in their specifications.

I import and distribute for Brymen in most of South America. Brymen does not make bench top meters. How can anything I sell be in competition with a VC8145? Your accusation of shilling is unfounded and I didn't expect such an accusation from a person I thought was a reasonable and fact based thinker.

[Lightages]

Oh yes, from what I can see, the MASTECH MS8040 looks like a better buy. Sure it doesn't have 80,000 counts, but it seems to hold its accuracy better for the full range. This based on a reading of the specification of both and is not from experience. I think I would buy the MASTECH MS8040 over the Vici,and I don't like Mastech very much at all. But that is just my opinion.

[k2teknik]

As alm pointed out a long time ago, the AC measurement accuracy is horrible, worse than a joke. How do you guys reconcile that.

No problem, I can read the spec on the instrument and it is ok for me, I think other can do the same, and if they don't do so, just bad for them, you have to do your homework before you buy stuff no matter what stuff it may be.
It is not your decision to decide what is ok for me or other, your post stinks of professional jealousy.

[k2teknik]

Here are results of my reverse engineering attempt of the RS232 protocol: http://www.26th.net/blog/vichy-vici-vc8145-digital-multimeter-rs232-protocol/

Nice work, thank you.

[Wytnucls]

What is not specified in the specs is that, as the meter uses an AD737 true RMS converter, the first 10% at least of the AC ranges, are also unreliable. That doesn't leave much to play with.

[nctnico]

Utter nonsense. The ACV range is limited. If you stay within 75% of the range and between 50Hz and 20kHz it's accuracy is 0.8% of the reading +/-50digits. This is better than my (4.5 digit) Agilent U1241B handheld DMM which already is at 2% at 2kHz. At least Vici took the effort to characterise their meter properly so you have some clue what the readings outside the specs are worth.

I don't think it is nonsense what alm pointed out. How is 8% accuracy considered good if you exceed 75% of a range? 50 counts out at any reading? I have a handheld meter here that costs just a bit more and has  better specs IMHO. It is a matter of opinion because the specs are stated differently. 50-60Hz; 0.5%+3D, 40-500Hz; <600mV 0.8%+4D, <100V 1%+4D, <1000V 2%+4D, etc, and never worse than 3%+4D up to 3kHz.

You try to write bad things about the VC8145 every time. This time about a post from 2012. Why did you dig that up, quoted the wrong specs and say it is a joke without any technical merit? I know you import multimeters into South America. Why don't you start selling the VC8145 over there as well? Or is your competitor killing you with it?

Actually, in spite of your vitriol, I have considered buying one of these many times. Investigation has stopped me each time. When did I misquote specs? You are saying that alm quoted was a lie? If so, please show how the specs provided by Vici contradict his statements. I think I stand on my assessment based on the technical merit as stated by Vici in their specifications.

I import and distribute for Brymen in most of South America. Brymen does not make bench top meters. How can anything I sell be in competition with a VC8145? Your accusation of shilling is unfounded and I didn't expect such an accusation from a person I thought was a reasonable and fact based thinker.

Sometimes I need to tickle people a little.

Appearantly using the AD737 has a trade off. Vici appearantly choose to have accuracy over a wide frequency range (0.8% from 50Hz to 20kHz) and decided to live with the fact this chip doesn't support the full range of the input. Their decission results in a meter with a much higher accuracy over a wider frequency range than their competitors in the same price range. There is no denying that and I don't see why you have to be so negative about that because the slightly more expensive meter you quote is already at 3% at 3kHz. You can use the VC8145 for doing accurate measurements on audio signal levels. The meter you proposed is useless for that purpose.

@Whytenucls: That is probably why they specified +/- 50 digits. But this is an 80000 count meter so you can always reduce the range to get more digits as long as the result is less than 60000 in AC mode.

[Wytnucls]

The meter doesn't have a uA range. You can't measure less than 8mA RMS accurately.

[nctnico]

Welll..  At some point you have to spend more money. For measuring low currents you can use an external device like a shunt or Dave's uCurrent.

[Lightages]

It is not your decision to decide what is ok for me or other, your post stinks of professional jealousy.

I asked for opinions on how the stated specs are not a problem for others so maybe I could see things differently. In what way could I have professional jealousy in relation to the subject?

You guys are reading far too much into my opinion and a question. If I didn't want to know how the specs were not a problem and how I might have been mistaken, I would have not even bothered to post. 

[Lightages]

Appearantly using the AD737 has a trade off. Vici appearantly choose to have accuracy over a wide frequency range (0.8% from 50Hz to 20kHz) and decided to live with the fact this chip doesn't support the full range of the input. Their decission results in a meter with a much higher accuracy over a wider frequency range than their competitors in the same price range. There is no denying that and I don't see why you have to be so negative about that because the slightly more expensive meter you quote is already at 3% at 3kHz. You can use the VC8145 for doing accurate measurements on audio signal levels. The meter you proposed is useless for that purpose.

OK fair enough. Now I have a reason why the VC8145 could be better for some things despite the specs it has. Thank you for a rational and non-insulting answer.

@Whytenucls: That is probably why they specified +/- 50 digits. But this is an 80000 count meter so you can always reduce the range to get more digits as long as the result is less than 60000 in AC mode.

And thus the reason to know the limitations of your equipment. Everything has a trade offs. Personally, and IMHO, for me, my use, I could not live with this meter, for me, my use. Is that clear enough?

[dadler]

Don't be too offended by Lightages'(s?) opinion regarding DMMs.

He already hates another meter that doesn't even exist yet 

[Lightages]

Don't be too offended by Lightages'(s?) opinion regarding DMMs.

He already hates another meter that doesn't even exist yet 

[k2teknik]

You guys are reading far too much into my opinion and a question. If I didn't want to know how the specs were not a problem and how I might have been mistaken, I would have not even bothered to post. 

If you do not like this instrument then that is ok with me, but why do you have to post (repeat what you had told before) your comments when it has absolutely nothing to do with what was the tropic when you posted yesterday?

FYI, somebody was exchanging experiences about communication with the instrument, there was nothing about the instruments measurements spec. You have already told, a long time ago, that you dislike the thing, why do you have to repeat this?
The bad performance, spec. of the instrument had been debated for a long time and every body that wanted to masturbate over this had had there chance, why do you have to continue to make noise?

[Lightages]

So because I was reconsidering this meter once again, and I had a question on how to reconcile what alm had stated. If you bothered to read my explanation before making your statement about me it would have saved some time. So my question wasn't to your liking. Hmmm, let me see. This thread is about the VC8145 and I wanted to discuss it. I am sorry I transgressed your rules that this thread was only to discuss the communications protocols. I will remember to ask you if it is OK to post my opinion and questions here. Are there any other threads which you are lording over that I need your permission to post on?

[k2teknik]

So because I was reconsidering this meter once again

You never even try to reconsidering this instrument (why should you, you have most likely many other quality instruments to choose from), you just wanted to show off how clever and smart you are on quality measurement instrument, that is all you wanted.

This thread is about the VC8145 and I wanted to discuss it

No, bs, read my above comments.

I will remember to ask you if it is OK to post my opinion and questions here

You are lying, you will never ever follow my guidelines. I will even give you more advice, keep you sale talk in your own sales-room.

And, no, I do not feel insulted because some people speak badly about an instrument I own, I know that a low priced instrument comes with some trade off's on spec, functionality, stability and price. I do have quite a few other instruments, and with much better spec and acceptable labels on the front, to choose from, but it doesn't change that for some task my VC8145 is the best choice, or just good enough for the job.

[Lightages]

Sale talk? WTF am I selling? I guess you have a problem with English as this is the only reason I can think you would be attacking me personally. I am sorry you don't care to take me at my word. Have a nice life.

[nctnico]

@Whytenucls: That is probably why they specified +/- 50 digits. But this is an 80000 count meter so you can always reduce the range to get more digits as long as the result is less than 60000 in AC mode.

And thus the reason to know the limitations of your equipment. Everything has a trade offs. Personally, and IMHO, for me, my use, I could not live with this meter, for me, my use. Is that clear enough?

That is your choice but I can't shake the feeling you dismiss the VC8145 because the manufacturer printed an accuracy of 8% for a certain input signal range. Personally I appreciate a manufacturer for being that honest. Other manufacturers often don't print such numbers to keep make their products appear very accurate even though the range is very limited. Just try to find a DMM for the same price which has an accuracy of 0.8% between 50Hz and 20KHz. I don't think you'll find any. You'll have to go into the >$600 5.5 / 6.5 digit territory to find a DMM which matches that specifiction. IMHO the VC8145 is a real gem if you can look past the rough edges. The designers clearly put a lot of thought into which useful features they could put into it while keeping the price low.

[Lightages]

Fair enough. Like I said, now I see your point on why the specs are not as bad as they look from first glance. I perhaps did not word my opinion and question in a way that was how I really wanted to represent myself. So yes, it appears to be a very good meter for what purposes you have mentioned. If you are doing audio work and need a meter to handle this then it is even a better value. I overlooked this possibility and that is why I asked how to reconcile the specs.

I had other priorities in what I wanted so I made a choice to buy something else but if I need a second budget bench top meter it probably will in the running again.

[Wytnucls]

@ nctnico
You seem to dismiss the published specs of other manufacturers as fanciful, while accepting Vici's ones without question. I don't believe for one minute that the meter can achieve true RMS 0.8% accuracy all the way up to 20kHz. Did you test those claims?
When I do a meter review, I check the meter published accuracy against known standards and state the areas where it is lacking, with supporting figures. That is what most readers would expect, to form a valid opinion about any DMM.
Your short review brushes over the serious limitations of the meter and comes across as fanboism.
Most of the flaws had to be brought up by others, working from the manufacturer's manual.

[nctnico]

@ nctnico
You seem to dismiss the published specs of other manufacturers as fanciful, while accepting Vici's ones without question. I don't believe for one minute that the meter can achieve true RMS 0.8% accuracy all the way up to 20kHz. Did you test those claims?

You are also missing the point I'm making. Other DMM manufacturers use a true RMS solution which is accurate over the full input range but has a limited frequency span. These meters are clearly intended for work on mains. Vici however choose a solution which makes their meter suitable for audio work.

BTW: I just did a quick test with a sine wave at 1V RMS (8V range). The meter reading stays within 1% between 20Hz and 80kHz.

[Mayor C]

I don't know about this forum, I came here to learn about electronics, swap ideas and exchange techniques. I came to this thread to learn about an entry level bench multimeter. It is under $200 and does a lot of things reasonably well. What I see  instead in ten pages is about ten good posts, the rest are guys trashing the meter like people paid $2000 for it and puffing out their chest with huge superiority complexes. People posted that the box is empty, of course it is!!!  It was made to fit a certain footprint. People are trashing it because it doesn't do a good job on mains voltage, duh it is a bench multimeter, not really intended to go to the jobsite. I see people saying that you would be better off buying a used meter on ebay, not everyone can afford to gamble buying used equipment, this has a warranty, this does alot and will get them by, if they can afford more later they can always sell it and upgrade later. Very few people are saying anything constructive. k2teknik added some great comments as did alm and nctnico. For those with negative comments perhaps they could do comparisons with other bench meters in the under $200 category, that's what should done in a thread like this.

I don't no why the mods don't clean up this thread, take out 90% of the no use negative comments, this one too and get the forum going where it needs to be. Technical, not emotional.
This is just sad.

[Wytnucls]

Pfff. Two posts and already asking mods to clean up the site. This is Australia, where free speech prevails. Get used to it.

[Wytnucls]

@ nctnico:
You need to run that test again. Use a proper reference this time. A 1% RMS voltage accuracy at 80kHz with a 4 1/2 meter would make the headlines around the world, if it was true.
6 1/2 bench meters like the Fluke 8846A and Agilent 34401A barely manage 0.7% up to 100kHz.

The Vici manual says 0.8%+50 up to 20kHz and then 5%+50 up to 50kHz. Above that, accuracy should fall off the cliff.

If you maintain that your test is valid, perhaps you should make a video, so that everybody can rush and buy a VC8145 tomorrow.

[nctnico]

I don't have a leveled generator. The SDG1010's output level I used is flat within 1% up to 100kHz.

[sync]

6 1/2 bench meters like the Fluke 8846A and Agilent 34401A barely manage 0.7% up to 100kHz.

They are much, much better in real life. I made a quick test with my Keithley 2000 (calibrated 2008), HP 34401A (calibrated by myself) and for fun two low-end meters. Source is an old Russian B1-9 AC calibrator set to 1.00000V.

freq    K2000     34401A    UT-71C   UT-61E
  20    0.99963   0.99949   0.9877   0.9936
  50    0.99990   0.99973   0.9961   1.0001
 100    0.99997   0.99980   0.9975   1.0018
 200    1.00003   0.99991   0.9978   1.0028
 500    1.00003   1.00001   0.9982   1.0033
  1k    1.00006   1.00004   1.0003   1.0030
  2k    1.00006   1.00006   1.0043   1.0020
  5k    1.00009   1.00010   1.0089   1.0001
 10k    1.00010   1.00014   0.9962   1.0010
 20k    1.00017   1.00019   0.9811   1.0083
 50k    1.00015   1.00003   0.9826   1.0575
100k    0.99993   0.99964   0.9913   1.2083

[Lightages]

I don't have a leveled generator. The SDG1010's output level I used is flat within 1% up to 100kHz.

I tried to find this spec listed somewhere. All I can find is that it is:

Vertical accuracy 100 kHz sine ±0.3dB+1mVpp of setting value
Amplitude flatness compared to 100kHz sine,5Vpp ±0.3 dB (or close to 3.5% if I calculated it correctly)

Did you actually measure the flatness of yours?

[nctnico]

I just Googled for the SDG1000 flatness spec and quoted the first I found. I guess Siglent changed the specs or measured them differently nowadays.

[inoxidabile]

Hi everybody ! 

I was looking for a software to the aim of connect VC8145 to pc.
The utility sent in the cd with the DMM was very bad, so I hope there is something better... I tried several softwares, like UltraDMM but no one runs. 

maybe someone could suggest me something (if any)?
Thanks a lot!

[k2teknik]

The utility sent in the cd with the DMM was very bad

Yes, especially if you have the character comma (,) as decimal separator in your windows OS setup, then the sw do not work at all.

maybe someone could suggest me something (if any)?

The SW for UNI-T UT70C works with the VC8145, except that the decimal point is in the wrong position (Uni-t UT70C is 8000 counts, VC8145 is 80000 count).

[pascal_sweden]

I recognize that the VC8145 does not have the same accuracy as the A-brand 6.5 digits meters, but do you really need that level of accuracy for most electronic projects?

If we assume that accuracy is good enough for most electronic projects, what are the real big deficiencies of the VC8145? Are we talking about missing features, safety issues?

I am happy with the build quality of the Vichy VC97 portable multimeter, and now consider the VC8145 bench multimeter as a nice addition. Not concerned about the accuracy, but want to check here about the big features I would be missing out, or what the potential safety issues are.

Note that I will only use it for low voltage applications limited in 100MHz bandwidth range.

Of course it would be cool to own a HP 3458A like this one for show-off

But definitely not in my budget and no need for the accuracy.

[Wytnucls]

Some people are perfectly happy using 10$ 3 1/2 digits DMMs for their projects. So, it's all about your needs and budget.

[SeanB]

+1 on that, I was using one today, as I wanted an extra meter to check while I had the other one in use. Always handy to have one or three around.

[Lightages]

I would say that the vast majority of people really don't need anything more than 3-1/2 digit (2000 count) multimeters. The extra digits and accuracy only really become useful for some very specific needs. I think that 10000 counts would be all that any general hobbyist would ever need. Of course there will be exceptions.

We are spoiled with a richness of cheap choices now.

[nctnico]

3.5 digits isn't enough. You need at least 4.5 digits. With 3.5 digits you are missing a part of the useful range. For example for 20V you need to select the 200V range with leaves 3 digits for display 20.0. With a usual accuracy of +/- 5 digits you don't know whether you are looking at 19.5V or 20.5V when the meter displays 20.0V. The accuracy of the reading is +/-2.5% in that case.

[pascal_sweden]

I noticed that the (-) terminal on the Vichy VC8145 displays a ground symbol.
Does that mean that this bench multimeter does not have an isolated front-end?

[Wytnucls]

3.5 digits isn't enough. You need at least 4.5 digits. With 3.5 digits you are missing a part of the useful range. For example for 20V you need to select the 200V range with leaves 3 digits for display 20.0. With a usual accuracy of +/- 5 digits you don't know whether you are looking at 19.5V or 20.5V when the meter displays 20.0V. The accuracy of the reading is +/-2.5% in that case.

Most 10$ meters go up to 4,000/6,000 count these days, with accuracies around 0.8%+3 digits. No real problem there.

[nctnico]

I noticed that the (-) terminal on the Vichy VC8145 displays a ground symbol.
Does that mean that this bench multimeter does not have an isolated front-end?

No. If you look closely you'll see the symbol refers to a line between + and -. It meens that there is a limit to input voltages and ground.

[inoxidabile]

@ k2teknik :
Hello, thanks a lot for suggestion!
The UT70D software runs well and i's good enough for a common use.
It's a pity for the wrong position of decimal point, as You said.

[k2teknik]

It's a pity for the wrong position of decimal point, as You said.

I found this sw https://www-user.tu-chemnitz.de/~heha/hs/UNI-T/ yesterday, it is more or less universal (for Uni-t products, and there is info on some Uni-t instruments RS232 protocols) I had just try it with the UT79D settings and it shows the right decimal point, but the logging is with wrong decimal point, but the sw looks better that the one from Uni-t and the one for the VC8145.

This sw should be able to use DDE with LabVIEW and MS Excel (maybe more?), but this out of my scope.

[inoxidabile]

I saw it some days ago, but in my pc sometimes it doesn't run (com port setup?)
Anyway, I agree with You, a great job of reverse enginnering has been done and I understand it (more or less) even if german it's not my language.
I think it could be used, maybe with some adjustements, moreover it's a confirm that the protocol for UT70D is correct for VC8145, or at least, acceptable.

[dev26]

Here is my implementation of control software to the multimeter: http://www.26th.net/public/projects/vc8145/

[Dave92F1]

Here is my implementation of control software to the multimeter: http://www.26th.net/public/projects/vc8145/

It works great! Thank you!!! It runs fine on Win7 x64.

My only request is re the timestamp format in the .CSV file - if you formatted it YYYY-MM-DD instead of DD-MM-YYYY, then the timestamps would sort properly (in a spreadsheet) when a run goes thru a end-of-month or end-of-year boundary.

(See http://nerdfever.com/?p=1863 for more details.)

[pascal_sweden]

How come some suppliers sell it for over 340 EUR?

http://www.benl.ebay.be/itm/VICHY-VC8145-4-5-inch-LCD-7-8-digit-Auto-ranging-Bench-top-Digital-Multimeter-/301614859290?pt=LH_DefaultDomain_101&hash=item4639a5841a

Is it the same model?

The average price seems to be around 150 EUR, so I don't understand the big price difference.

[k2teknik]

My only request is re the timestamp format in the .CSV file - if you formatted it YYYY-MM-DD instead of DD-MM-YYYY, then the timestamps would sort properly (in a spreadsheet) when a run goes thru a end-of-month or end-of-year boundary.

These things can be sorted out when you import the csv file, no reason to use any specific date format (as long as you know the format your self).
When importing into Excel you just choose that this column is a date and then what format it is, and Excel convert the date to an Excel date format.

[k2teknik]

How come some suppliers sell it for over 340 EUR?

They call it "Making money", you may ask "Why do some people pay this amount of money when the can buy the same unit at a lower price somewhere else?".

Is it the same model?

Yes.

The average price seems to be around 150 EUR, so I don't understand the big price difference.

I paid 125 USD for my instrument all included, so it pays off to search before shopping.

[pascal_sweden]

Can you send the link to the 125 USD dollar deal? =)

[Dave92F1]

My only request is re the timestamp format in the .CSV file - if you formatted it YYYY-MM-DD instead of DD-MM-YYYY, then the timestamps would sort properly (in a spreadsheet) when a run goes thru a end-of-month or end-of-year boundary.

These things can be sorted out when you import the csv file

I suppose, but it's a needless extra step. ISO 8601 timestamp format (YYYY-MM-DD HH:MM:SS.FFF) sorts naturally, and is unambiguous.

Another suggestion: Since there's no way (that we know of) to recalibrate the Vici, how about adding an option for calibration offsets into the PC program:

CalibratedResult = (RawResult + CalOffset) * CalGain

It would have to be done separately for each measurement mode (V, A, ohms, etc.).

[Dave92F1]

Can you send the link to the 125 USD dollar deal? =)

Probably that was a long time ago. Best I could find was USD 150 or so. On eBay.

[k2teknik]

Probably that was a long time ago. Best I could find was USD 150 or so. On eBay.

Yes, it was a year or so ago, I used a seller from http://www.aliexpress.com/

[pascal_sweden]

Vichy VC8145 or Victor 8145? Which one to choose?

I read that build quality is better on Victor, but what about the specs?

And what about the price difference?

Does only Vichy VC8145 have RS232 interface?

[k2teknik]

Vichy VC8145 or Victor 8145? Which one to choose?

It is most likely not the same instrument, the Vichy is a 80000 count the Victor is a 33000 count, Victor seems not to have RS232
Victor 8145A: http://www.chenxiulian.com/ArticleShow.asp?ArticleID=839
Victor 8145B: http://www.china-victor.com/english/en/product_data.aspx?ClassID=173&ID=160
Vichy 8145: http://www.vicimeter.com/en/productshow.asp?sendid=8

[pascal_sweden]

So although the build quality is not that good on Vichy, it has much better specs than Victor (higher count and RS232 interface). Good to know!

Did somebody already do a tear down of the Vichy VC8145 bench multimeter and inspect the build quality and input protection on the PCB board?

Are there HRC fuses (High Rupture Capacity) or glass fluses?
What about MOVs (Metal Oxide Varistors)?
What about input protection PTC thermistor and large input protection resistor?
What about 10A current shunt?

[nctnico]

Look at the pictures here:
https://www.eevblog.com/forum/testgear/vc8145-thread-it%27s-here-finally/msg174988/#msg174988

[electronicnoobblog]

Hello,

I have question for owners of VC8145:

Does back-light can be enabled all the time or You have press button every time You want to see something?

(i came across some bad design, clone from handheld where You have to press it every time...
it was crazy...
maybe You save planet but meantime you end up in mental hospital for long treatment witch electric shock so basically it does not pay-off...)


If someone saw any video review it will be nice -> Sharing is caring!
Sometimes it's hard to base only of chines description.
I mean i saw some pictures in this topic from inside... looks nice at that price range, but sill that does not give overall expression abut measurements.

150 usd is a wired price range, to expensive to buy "just like that and thrown away if not nice like a 1 dollar crap" and to cheap to expect working like fluke or hp.

If someone could tell me, like a friend how does it goes in everyday working scenario.

Im asking something like this:
it have lot of buttons, does it for example need to make some multiple stupid clicking to just change from resistance to volt meter ?

Im please ask for that kind of comment abut this multi-meter

Regards

[nctnico]

The backlight if off by default but somebody posted a modification (a wire) which makes the backlight go on by default.
You can select between various modes with one button press. Only for the temperature measurement you need to press the select button to show the temperature of the probe. Otherwise it will show it's internal temperature.

[Dave92F1]

somebody posted a modification (a wire) which makes the backlight go on by default

That was me. But I ended up removing the mod, and I don't recommend it.

Turns out that it only works about 90% of the time. The other 10% you turn it on and it stays dark; if you did the mod then the button doesn't work, so you have to turn the meter off again, wait a few seconds and try again. I found that worse (1 in 10 times) than having to press the button each time.

I looked into installing a PIC to wait 500 mS then push the button, but the levels inside didn't seem to make that easy (I forget the details).

So I just removed the mod and now I press the button for the backlight.

I really like the meter, tho. It's accurate and has a very good UI (easy to use), other than the backlight thing. 

It does beep a lot. If that bothers you, don't get it. It doesn't bother me very much.

[electronicnoobblog]

The backlight if off by default but somebody posted a modification (a wire) which makes the backlight go on by default.
You can select between various modes with one button press. Only for the temperature measurement you need to press the select button to show the temperature of the probe. Otherwise it will show it's internal temperature.

somebody posted a modification (a wire) which makes the backlight go on by default

That was me. But I ended up removing the mod, and I don't recommend it.

Turns out that it only works about 90% of the time. The other 10% you turn it on and it stays dark; if you did the mod then the button doesn't work, so you have to turn the meter off again, wait a few seconds and try again. I found that worse (1 in 10 times) than having to press the button each time.

I looked into installing a PIC to wait 500 mS then push the button, but the levels inside didn't seem to make that easy (I forget the details).

So I just removed the mod and now I press the button for the backlight.

I really like the meter, tho. It's accurate and has a very good UI (easy to use), other than the backlight thing. 

It does beep a lot. If that bothers you, don't get it. It doesn't bother me very much.

Thank You, that's informing, i think i got everything what im asking for.
Pressing button once is not a problem.


Regards

[dev26]

I looked into installing a PIC to wait 500 mS then push the button, but the levels inside didn't seem to make that easy (I forget the details).

So I just removed the mod and now I press the button for the backlight.

Remove R70; then connect IC8, pin 12 with base of Q11 using resistor about 10k. Now the backlight is default ON, but the button can be still used.

It does beep a lot. If that bothers you, don't get it. It doesn't bother me very much.

Use the duct tape, Luke!

[pascal_sweden]

You could probably get in touch with the factory and ask them for a firmware update.
Is there a JTAG connector to the main processor?

[k2teknik]

Remove R70; then connect IC8, pin 12 with base of Q11 using resistor about 10k. Now the backlight is default ON, but the button can be still used.

Well seen, Q11 is a 4013 (Dual D-Type Flip-Flop) with a Q and an inverted Q output, so just switch to the inverted Q and the display light function will be reversed.
I was lazy and just lifted pin 13 and then shorted the pad under pin 13 with pin 12

Use the duct tape, Luke!

I desolder the buzzer.

[Dave92F1]

Remove R70; then connect IC8, pin 12 with base of Q11 using resistor about 10k. Now the backlight is default ON, but the button can be still used.

Thanks! I'll give it a try.

Use the duct tape, Luke!

I can't. I need the continuity beeps.

[dev26]

Use the duct tape, Luke!

I can't. I need the continuity beeps.

That is the idea - the beep is still here, but is much softer and quieter.

[Dave92F1]

Remove R70; then connect IC8, pin 12 with base of Q11 using resistor about 10k. Now the backlight is default ON, but the button can be still used.

I confirm it works great.

Even easier, just turn R70 by 90 degrees, then connect the loose end with a wire, as shown.

(BTW, be sure to clean the keyboard contacts on the other side with alcohol before reassembling, if there's any chance you touched them with your fingers.)

May I ask how you figured this out? If you have a schematic for the VC8145, could you please post it?

[dev26]

No, I have no schematic. I just followed wire from the button and saw it ends on clock pin of a 4013. Then looked to other pins - Q is connected with base of some transistor which controls the backlight's LEDs.

It's known way to use a flip-flop - "!Q" to "Data" (via R67), "Clock" to a button (R39+C8 for anti-bounce, R40 - push-down) , a delay circuit (R69+C36) to "Set". Result may be taken from Q or !Q.

[Dave92F1]

OK, thanks.

Unfortunately I backed out the mod - it vastly reduces the LCD contrast when viewed from straight-on or below. (It was bad to start with; with the mod it's worse).

[Dave92F1]

Hm. Replacing R41 (68k ohms) with about 30 ohms vastly improves the LCD contrast.

I don't fully understand why it needs to be such a low resistance. It seems to have more to do with the current flowing thru R41 (into the display controller) than the voltage.

[nctnico]

That is probably the contrast adjust voltage for the LCD display.

[pascal_sweden]

Does the manual document a procedure to calibrate the multimeter yourself using an accurate source?

Most expensive multimeters can be calibrated yourself using a detailed and documented procedure.

Or do you need to send it in to the factory?

[k2teknik]

Does the manual document a procedure to calibrate the multimeter yourself using an accurate source?

No, my version do not.

Or do you need to send it in to the factory?

That will most likely cost too much compare to the cost of the instrument it self.
Contact a calibration service near your place and ask them if they can calibrate it for you.

But maybe you do not know the difference between calibration and repair?
Calibration is a check if the instrument is within it's spec. the result is a yes/no, and maybe a more detail report.
Repair is what you do to make it return to spec. if it fails in the calibration process.

[pascal_sweden]

Are there many trim potentiometers on the PCB board?
Do they have a text marking?

Who has an email address to the manufacturer? Maybe we could contact them and ask for the detailed calibration procedure.

[k2teknik]

Who has an email address to the manufacturer?

Here you go: http://www.vicimeter.com/en/contact.asp

Maybe we could contact them and ask for the detailed calibration procedure.

Do not expect too much, I had tried a few times to contact them no response so far.

[torch]

Hm. Replacing R41 (68k ohms) with about 30 ohms vastly improves the LCD contrast.

Earlier in this thread you indicated that the light mod affected the contrast and therefore you reversed it. So in the end, did you re-do the light mod after swapping out R41? How did that work out?

[torch]

Way, way, back in this thread, someone asked about the >80Mohm measurement range. Today I tried measuring the 1090 Mohm 2% resistor in a recently acquired Heathkit 336 VTVM HV probe. Obviously neither the accuracy of the Vici nor the accuracy of the ~50 year old resister can be assured, so the following should not be accepted as canon!

The reading tends to wander up and down the scale a bit. Even breathing on the resistor changes the measured value. However, the wandering did generally stay within the supposed 2%, centered around 1092 - 1094 Mohms or so most of the time, dipping to 1078 if held a certain way and climbing to 2011 if held another way. The most stable and closely centered method seemed to be laying the body on a piece of wood with either end hanging in free air, connecting the probes with alligator clips.

[gatoazul]

Hi,

im interested in this meter.
How is it going over this years in terms of accuracy?
Could someone who owns this bench multimeter do some accuracy tests?

[nctnico]

Earlier this year I checked both my VC8145s against a Keysight 34461A and both where within spec. The VC8145 has a decent voltage reference inside so I don't expect it to wander off much.

[gatoazul]

Do you Know whats the reference voltage used in VC8145 (Chip?)
?

[nctnico]

It seems I took one of mine apart 4 years ago:
https://www.eevblog.com/forum/testgear/vc8145-thread-it's-here-finally/msg174988/#msg174988

I re-uploaded the pictures today because Imageshack has stopped.

[torch]

Mine's been powered up 24/7 for about a year now and it seems to be as accurate as when I got it. Not that I have a Keysight to check it against or anything. (I've been meaning to buy one of those inexpensive calibrated voltage standards. Maybe it's time to toddle off to eBay). But comparing voltages to other volt meters and frequency measurements against my faithful Rigol, I don't think it wandered very far. Even the on-board square wave generator seems to be on the money, which would be great if it wasn't limited to 5KHz  .

I really like the large, clear, easy to read display.

[ziplock9000]

@ k2teknik :
Hello, thanks a lot for suggestion!
The UT70D software runs well and i's good enough for a common use.
It's a pity for the wrong position of decimal point, as You said.

Do you have a link to it please?

[k2teknik]

Do you have a link to it please?

Try https://drive.google.com/drive/folders/0B4Jyby-tjH5oMkdsX0pGT2piZkk
I did not test any of these, but the link is from Uni-T them self http://www.uni-trend.com/productsdetail.aspx?ProductsID=600

[pascal_sweden]

It seems I took one of mine apart 4 years ago:
https://www.eevblog.com/forum/testgear/vc8145-thread-it's-here-finally/msg174988/#msg174988

I re-uploaded the pictures today because Imageshack has stopped.

Do you have more than one? How many?

[nctnico]

I have two and I'm thinking of getting one or two more but that depends on whether I can score one or more of the GW Instek DMMs from the ITT auctions. Sometimes I need more DMMs in a test setup.

[torch]

Hi,

im interested in this meter.
How is it going over this years in terms of accuracy?
Could someone who owns this bench multimeter do some accuracy tests?

I'm sorry it took so long, but I ordered this reference module on eBay and it just arrived yesterday. Vendor claims it is measured with a calibrated HP3458A and provides calibration data indicating the actual outputs are 2.50175, 5.00392, 7.50688, and 10.00845 vdc.

I measured the 2.5, 5.0, and 7.5 v outputs 3 different ways: Auto, Rel and manually increasing the range one step.

So, for the 2.50175 vdc standard output, the VC8145 measured:
2.5013 (auto)
2.5022 (rel = -0.0008)
02.500 (manual range)

for 5.00392 vdc standard output:
5.0038 (auto)
5.0046 (rel = -0.0008)
05.002 (manual range)

for the 7.50688 vdc standard output:
7.5069 (auto)
7.5077 (rel = -0.0008)
07.505 (manual range)

The 10.00845 output measured 10.007 in auto and 10.006 in manual, although the rel read 0.

I have had this meter well over a year now and it is generally left on.

Edit: so DCV accuracy works out to +/- 0.02%. Spec is +/- 0.05%+5, so mine is in spec on that range, anyway.

[k2teknik]

I checked my VC8145 vith a reference module from eBay too and I cheked all my multimeters, my best one is a Solartron 7150 so I show that one just for a reference.
So my VC8145 is not within spec and that is ok with me, on the other hand I had not seen any drift too.

VoltReference  Solartron 7150            VC8145
  2,50124          2,50152  -0,011%      2,5031 -0,074%
  5,00253          5,00307  -0,011%      5,0068 -0,085%
  7,50426          7,5051    -0,011%      7,5109 -0,088%
10,00489        10,00595  -0,011%    10,014   -0,091%

[mentaldemise]

Could someone provide an image of the CD with the VC8145? I got mine today but the CD is bad so I can't install the app to use the RS232 interface.

[mentaldemise]

Nevermind. I left the house for 2 hours, returned, and now it won't display anything and the beep is muted. Time for a return.

[k2teknik]

.. now it won't display anything and the beep is muted. Time for a return.

Had you try to disconnect the power, wait a minute, reconnect power and then turn it on?
It is a Chinese designed unit sometimes it do strange things.

[sn4k3]

My VC8145 temperature function never worked. It shows only current temperature i think.
I test with other probes as well.
Anyone have this issue? I have done the backlight ON mod

[coromonadalix]

hi @ll   is there a known calibration procedure for these meters ?

[nctnico]

My VC8145 temperature function never worked. It shows only current temperature i think.
I test with other probes as well.
Anyone have this issue? I have done the backlight ON mod

You have to press the select button to toggle between internal and external sensor.

[sn4k3]

My VC8145 temperature function never worked. It shows only current temperature i think.
I test with other probes as well.
Anyone have this issue? I have done the backlight ON mod

You have to press the select button to toggle between internal and external sensor.

Dam that's did the trick. Thank you 

[ultrablog]

Hi

I think my Vici 8145 developed a problem. I wonder if there's a reset procedure or some known issues?
I don't think I should send it in for repair, it came from china and it's a few years old, so very doubtful that is a good idea. The shipping would kill me, and with no guarantee to see it back repaired...

Most of my ranges work. VDC, VAC, mV, mA, 20A, Ω all seem fine. The button for backlight too. But the other buttons adjacent to those react weird. They beep, and the mode changes, so it's not that the button is dead. But the functions are fubar. For example, selecting temp mode displays Ω in the display. Selecting capacity displays mV, and so on. It's erratic. Sometimes it also goes wild beeping. I'm having trouble so determine when that happens if it goes berserk or that it switches ranges continually.

This post is twofold... in a way to warn people, but hopefully someone has a good tip to try and reset it to its working order again...

[nctnico]

Perhaps check the ripple on the power supplies. Or the rubber mat with the bushbuttons got dirty and needs to be cleaned. It could be a bad solder joint too; shouldn't be hard to find if you follow the connections to the keypad.

And if you think this is a problem for cheap Chinese products: I had a similar problen on a >$20k Lecroy scope where it turned out a whole bunch of diodes in the front panel switch matrix where broken because they used a diode which is unsuitable for the purpose.

[coromonadalix]

Does anyone made a eeprom dump ??   wanna check something ...

[MBY]

One thing I HATE about this meter: It beeps loudly anytime, anywhere. Several beeps on boot, beeps on every button press, beeps on ranging.
One thing I like about this meter: Even if the continuity beep isn't latched, it's fast and loud.

Removing the buzzer or wrap it in something doesn't cut it, because I want the loud beep when doing continuity.

Solution:
Turns out that the relays are high-side switched and in diode/continuity mode, only the relays K1 and K3 is activated. The other modes has other combinations, but K1=on, K2=off, K3=on, K4=off seems to be unique for this mode. So a simple diode AND-function could be used to only enable the buzzer in the diode mode. The buzzer rests at +6.66V and the relays are 5V-driven with respect to ground. So the LED is to avoid that current from the 6.66V rail (or whatever it is) creeps into the 5V circuits. Any red or green LED with a forward voltage of about 1.6-2V should do it. I don't think the component values are critical in any way. 1N400X or 1N4146 is probably fine, or even two LEDs for the "AND" (negating the need for the pull up LED). I just happened to have 1N5819 schottkys. The buzzer is dynamic, so no need for a "return path" or relying on the implicit back diode in the 2N7000, so a bipolar transistor will probably also work just fine.

If you want a quiet beeping in the other modes, just parallel the DS on the transistor with whatever resistor feels right (the buzzer is 16 ohms).


Here is the back side of the analog PCB. There is no need to remove the shield as the relay is accessible from the back side. Don't mind the blue LEDs, I just mounted them there in order to see which relays were on in which modes.

...and here is the "ghetto mod" itself.

It work very well, the buzzer is off in all modes except for diode/continuity. The instrument even "feels" more professional, as you now hear the relay switching when you change modes, something that the buzzer shouted down before.   

Edit: So the "embedding" of the pictures didn't work. Sorry if the context got messed up, but you have the pictures below.
Edit2: Do'h! Naturally I misspelled "marked" in the schematics as "maked". Another thing to note, is that the buzzer itself has a +-marking and as far as I can tell, it was mounted backwards on the PCB. And yes, I damaged the plastic of the buzzer with my soldering iron as you see in the pictures... 
Edit3: Clarification: The "positive terminals" on the relays refers to the *coil*, not any of the contacts.

[Microcheap]

Thanks for sharing. I will definitely have to try that mod.