Bench 6.5 digit - most bang for the buck?

[alank2]

Zoro is running 25% off today and they have a Fluke 8845A for $1080-25%=$810 shipped.  I've looked at the Agilent meters they have, but I don't think they have a 6.5 digit one.  For the money these days, what is the best bang for the buck?  I've never had a bench meter, so this will be a step up from the mostly handhelds I use.

[dr.diesel]

The 8845A/8846As are superb meters with a good history and very mature.  I would not hesitate myself even though they are a bit old.

IIRC an additional digit of resolution is available via serial, don't recall if mostly noise, Robrenz has a thread about it.

[esmIII]

Did you look here https://www.eevblog.com/forum/testgear/multimeter-spreadsheet/] [url]https://www.eevblog.com/forum/testgear/multimeter-spreadsheet/[/url]

[alank2]

Thanks guys, that spreadsheet is impressive.

[XFDDesign]

I'm biased towards Fluke. That you have the option to get one at that price is wild.

[alank2]

I'm biased towards Fluke. That you have the option to get one at that price is wild.

Anyone can!

http://zoro.com has the coupon on their main page today.  25% off until the end of today.

[georges80]

I have an 8845A, nice bench meter. Fortunately in my case I scored it for free from a consulting/contracting gig (plus other TE when they shutdown the company).

I have invested in a nice 4 wire (in 2 leads) probe set to make use of it's low resistance measuring capability. Even when front panel 'off' (standby) it still is internally on (unless you also turn the rear switch off) since I presume it keeps the reference circuitry etc powered up so you don't have to wait for it to warm up each time.

cheers,
george.

[AlphZeta]

How about a Keithley 196? It can be had for less than $200 and is a great meter to have

[saturation]

Bang for buck non-professional use DVM, i.e., no current range, is an HP 3456a.

[alank2]

I ordered the 8845A - it will be my first ever bench meter.

[krivx]

How about a Keithley 196? It can be had for less than $200 and is a great meter to have

If you are going cheapest then some of the Solartron 6.5 digit meters regularly go for less than $100

[nctnico]

Zoro is running 25% off today and they have a Fluke 8845A for $1080-25%=$810 shipped.  I've looked at the Agilent meters they have, but I don't think they have a 6.5 digit one.  For the money these days, what is the best bang for the buck?  I've never had a bench meter, so this will be a step up from the mostly handhelds I use.

Maybe too late but I'd probably choosen a newer Keysight model because of the additional features. 6.5 digits sounds great but to measure using the full accuracy of a 6.5 digit meter you'll have to look at the probing solution very seriously.

[cncjerry]

Used 3456a is a great, stable, easy to fix meter for less than $200.  For slightly more money, you can get the predecessor to the 3458a, the 3457a.

Both meters need good, shielded, probes to perform to their best.  Also, the added advantage of the 3457a is the 7.5 digits available from the HIRES register.

I have a keithley 196 and that is a great meter as well.

[Gandalf_Sr]

How about the Agilent 34461A? They are offering free Labvue Pro software too https://www.eevblog.com/forum/testgear/free-benchvue-dmmfgdaq-pro/msg795758/#msg795758 and it costs $1086 from tequipment.net http://www.tequipment.net/Agilent/34461A/?readReview=1765b#tab-reviews plus you should be able to get 5% off with the EEVBlog discount.

[alank2]

Well, the 8845a arrived and I am pretty disappointed.  It will be going back.

I think the display is its Achilles' heel.  It isn't very bright even on its brightest setting - they probably have tweaked this in the firmware over the years in an attempt to make it last longer, but the display quality really is terrible.  Even on its bootup message there are obvious pixels and rows that are brighter than others.  I've never been a huge fan of graphic VFD's, but I am less so now.  I get the feeling that VFD is much better suited to segments than it is dots.

I am also disappointed with the way they implemented the display in firmware.  The main display has nice large digits, but anytime you get to any specialized display you end up with the same sized characters laid out in monospace font.  A good example might be how good the min/max/avg looks in my Fluke 289 vs. how terrible it looks on the 8845A.  Also, the flickery blinking is the result of poor screen implementation code in the firmware.  There is no reason for an instrument of this class with a super fast VFD to clear the screen and repaint it with such a delay that the user sees it flickering when going between functions.

The display is my biggest gripe honestly, but it runs pretty warm when on for awhile and I hear an odd 1 Hz ticking sort of sound coming from it as well.

The positives are that it seems to go up to 1 Mhz frequency even though it was supposed to only go to 300 kHz, given the sheet that arrived with it, it seems to be calibrated very well, the trendplot is cool, and it looks like its management features are very solid though I did not test them.  It does come with the cable (rs232-usb) which surprised me as I thought only the SU version came with that.

I'm going to save my $$$ and get a 34461A some day instead.

[MadTux]

Well, the 8845a arrived and I am pretty disappointed.  It will be going back.

You must be right handed. I guess Fluke made that thing to satisfy the left handed 10% of the population. Or they just screwed up and placed the inputs on the wrong side

[rgawron]

Regarding Fluke 6.5 digit bench multimeter, on the picture is what arrived to me. Note the lack of "Fluke" label on the yellow rectangle - would be hard to sell it later and convince anyone that the unit was not repaired/opened. I have replaced the device with a correct one in the online shop where I bought it and now is OK.

I have also contacted Fluke support and it seems that they really didn't care, I got email that they analyzing it and they stopped respond to my emails.

Just a tinny issue, but now I'm biased against Fluke - mainly due to their support.

[alank2]

You must be right handed. I guess Fluke made that thing to satisfy the left handed 10% of the population. Or they just screwed up and placed the inputs on the wrong side

  Well, I actually am left handed but I still like the inputs on the right too!

[XFDDesign]

I wonder if it isn't a dud unit. Not that the question is to dissuade the OP, they need to be happy with their buy. But I've got many Fluke units in my realm, none of which appear to exhibit this set of problems. Granted, they're all 8846a units and not the 8845a ones.

[alank2]

I wonder if it isn't a dud unit. Not that the question is to dissuade the OP, they need to be happy with their buy. But I've got many Fluke units in my realm, none of which appear to exhibit this set of problems. Granted, they're all 8846a units and not the 8845a ones.

It is tough to say.  This morning I turned it back on and for awhile no ticking 1 Hz noise, but then later on it was doing it again.  It seems to measure just fine.  I think I am really disappointed with the display more than anything else on it.

[XFDDesign]

It is tough to say.  This morning I turned it back on and for awhile no ticking 1 Hz noise, but then later on it was doing it again.  It seems to measure just fine.  I think I am really disappointed with the display more than anything else on it.

If it's really aesthetics of display, then return it and buy a USB based DMM. Nothing will beat the beauty of a desktop display. VFDs do their job well enough usually (though not in your case), but I was after an accurate bench meter to get readings from, the display just has to work well enough to communicate the information.

[commie]

Hi,

I bought the Fluke 8846A about 7 years ago, what a pile of stinking shit it turned out to be. The display was terrible and after awhile the display just gets dimmer and dimmer, so I flogged mine on ebay. The multimeter to have is keysight 34465A, they are top flight. The best Fluke bench meter is their 51/2 digit '8808', very nice.

Well cheers
Commie

[HKJ]

I bought the Fluke 8846A about 7 years ago, what a pile of stinking shit it turned out to be. The display was terrible and after awhile the display just gets dimmer and dimmer, so I flogged mine on ebay. The multimeter to have is keysight 34465A, they are top flight. The best Fluke bench meter is their 51/2 digit '8808', very nice.

There is obvious different opinions about the meter, my two 8846A are also some years old and have been used a lot, they are still very precise and I have no problem reading the displays. I do also have a 34465A, but it is much never and I have no idea if it will handle time as well as the 8846A.

[timb]

Hi,

I bought the Fluke 8846A about 7 years ago, what a pile of stinking shit it turned out to be. The display was terrible and after awhile the display just gets dimmer and dimmer, so I flogged mine on ebay. The multimeter to have is keysight 34465A, they are top flight. The best Fluke bench meter is their 51/2 digit '8808', very nice.

Well cheers
Commie

I've got a Tektronix DMM4020, which is a rebadged 8808A. Had it for about 2.5 years now and I absolutely love it. The VFD is super responsive, bright and fast. It boots instantly, has latching continuity, RS-232 interface, selectable speeds and the controls are very intuitive.

It's my daily use DMM. I have a 3456A for precision stuff. Had a Keithley 2000, but ended up selling it a few months back. (It needed to be calibrated, otherwise I might have kept it. My 3456A is NIST calibrated, so...)


Sent from my Tablet

[alank2]

If it had a segment display like the 8808A, I probably would have kept it.

[alank2]

SO what do you guys think of the Rigol DM3068 vs. the Agilent 34461A.  If I am understanding the specs/videos I see, it looks like the Rigol might have a higher counts - 2M vs the 1.2M of the Agilent - is this true?  I guess this is one thing that irks me about these things.  One manufacturer claims 6.5 digits and another does and with the "rounding" you don't really know.  In this case log10(1200000)=6.079 digits and log10(2000000)=6.301 digits.

[Macbeth]

I've got a DM3058E which is alright as the lowest possible denominator, but 6.5 digit - forget the DM3068 and go for Keithley 2000 and especially 2015's which are very cheap at the moment because they were sold to the phone companies and are now flooding the second hand market... (Guy in South Korea will let them go for $200 each if you can order a good pile, like 10 off)

And of course a HP 34401A is the classic that all college kids used. But the Keithley is so much better! cheaper! Who doesn't love a Keithley 2000 running up its 10Gohm voltage display?

[smgvbest]

I've got a DM3068 and a HP34401A.   I realize the HP is seen as a much higher quality meter and is serviceable were as the DM3068 is not.   
But side by side in measurements they are often <10mV off of each other on <10V range.  microvolts off usually in the lowest ranges.
In resistance reading 2W a few milli ohms off and 4W they are usually less than 2mOhm off as well.   I realize this can be big for professional and I am not saying the DM3068 is on par with the HP but depending on use the Cost vs function vs accuracy to me seems to be good.

So my question is what I am missing?   Just comparing common features not ones the DM3068 has the 34401A does not and visa-versa.

[commie]

SO what do you guys think of the Rigol DM3068 vs. the Agilent 34461A.

Get the newest Agikent 34461A or the 34465A, if you cant afford one get the Fluke 8808.

[HighVoltage]

I just got a great deal on an Agilent 34410A, probably one of the best 6 1/2 digit meters ever built.
If you look long enough, you can find them in the price range of a 34401A.

Great read on the GellerLabs website between the 34401A and the 34410A
http://www.gellerlabs.com/34401A%20AC%20zero.htm

[rdl]

I've just about talked myself into buying one of those Vici 8145 bench DMMs. At less than $30 per digit it looks hard to beat. I bet it'll be plenty good enough for anything I need to measure. All I have now is a cheap 4000 count rebadge bench style meter and a Fluke 87-III that I don't like to use because it burns through batteries too fast.

[Micke]

I just got a great deal on an Agilent 34410A, probably one of the best 6 1/2 digit meters ever built.
If you look long enough, you can find them in the price range of a 34401A.

Great read on the GellerLabs website between the 34401A and the 34410A
http://www.gellerlabs.com/34401A%20AC%20zero.htm

I also have a 34410A, and it is a great instrument! I had a 34401A before buying it, but sold the 34401A.
They look quite similar, but are quite different if you look closer!
I would say the 34410A is better in all ways except it has a fan with a high pitch irritating sound! (but I put a fan reduction device in my unit, now it is fine)

Extras on the 34410A:
* Better HMI, easier to navigate in menus etc.
* Display has two rows (showing for example Frequency and ACV simultaneously, or showing statistics (max, min, mean etc) simultaneosly with "live" data)
* Capacitance measurement
* Temperature measurement (NTC 2.2k, 5k or 10k or RTD 49R-2.1k)
* Extended AC/DC Amps range down to 100µA (but there are hacks to enable unofficial 10mA ACA range on 34401A, works fine)
* As mentioned before, superior AC measurement with direct sampling (like 3458A), specifications are very conservative! Crest factor up to 10 no problem!
* Resistance measurement to 1GOhm
* Can be used as standalone datalogger with internal non volatile memory of 50000 samples (20µs-3600s sample interval)
* Has LAN interface with built in web server, just surf in to the unit to configure or get readings!

BTW, here is how to enable 10mA AC range on 34401A:
http://www.keysight.com/main/editorial.jspx?cc=SE&lc=swe&ckey=1000001267:epsg:faq&nid=-536902435.536880933.02&id=1000001267:epsg:faq

[alank2]

So guys, what type of calibration document do these units come with:

Keysight 34461A/34465A

Rigol DM3068

If you have one of these and can post it, I'd love to see what they look like, how detailed they are, how close a unit is to ideal, etc.  The Fluke 8845A one I had (before I returned it) was pretty detailed.

[Tom45]

The certificate for my 34465 is attached below. I see I'm due for a new calibration. Not that I'm planning to do it.

[alank2]

Thanks Tom - that is what I was looking for.

[smgvbest]

Rigol doesn't give a test report.  only the certificate part
I'll scan one of mine and post sometime today


(edit: added DM3068 Cal Cert)
(edit: Just for fun I added my DP832 Cal)

Macbeth, Looks like same call equipment on our 832's also

[alank2]

Thanks Sandra.

[Macbeth]

I can confirm Rigol only give the summary sheet and no data.

Sandra, it looks like we got the same Fluke Calibrator, only mine was 11 days later than yours 

Also my DP832 for good measure 

[alank2]

Well guys, I've come to the conclusion that the 8845A is the 6.5 digit meter _I can afford_.  Zoro has 30% off today (still going) and that brought the price to $756 shipped.  On top of that they have a gift promo going where you can get an ipod touch or fluke 116.  So ... I ordered it again.  Hopefully this one won't have the 1 Hz buzzing noise, and at this price, I'll live with the display.  I would have preferred the 34461A, but it is $300 more and no gift.

[dr.diesel]

You've made the right choice, twice, lmao.

[alank2]

twice, lmao.

Oh yeah, this is how I do it.  You know you should have kept something when you miss it after you send it back...

[Micke]

Besides Agilent 34410A, I also have a FLUKE 8846A which I am very happy with.
The 8846A has one very big advantage compared to many other multimeters, it is fanless!
Before modding the fan on my 34410A, I tend to use the 8846A more often due to the irritating fan noise of the 34410A...

On the forum, free_electron has made a great teardown of a 8846A: https://www.eevblog.com/forum/reviews/fluke-8846a-teardown-9409/msg127654/#msg127654
I like those hermetically sealed laser trimmed resistor hybrids!
Other people on the forum have testified the 8845A/8846A is really stable over time, probably those hybrids are a big contribution to that!
Downside on the 8845A/8846A is the VFD display, which quickly fades, and "burns-in". But if you buy the multimeter new, it is likely not a problem, another story with equipment powered on 24/7 in a production line or something...

[HighVoltage]

I never had a 8846A, may be time to get on...

In regards to the 34410A, you are absolutely right, the fan noise is horrible, if you are sitting next to the meter. This was also one of the first mods I did, when I got my first 34410A a couple years ago. It is very simple to install a "quiet" fan and then the meter is perfect. Interesting, that Agilent thought to add the fan, although the 34401A also was a fan-less unit.

[alank2]

Downside on the 8845A/8846A is the VFD display, which quickly fades, and "burns-in". But if you buy the multimeter new, it is likely not a problem, another story with equipment powered on 24/7 in a production line or something...

The other forum member who said Fluke wanted $400 or so to replace the display was not pleasing to me (You can buy the 34461A display online for $60 or so I think I saw), but perhaps the $400 is for the entire display and front panel pcb with input buttons, etc.  I looked through some of the Noritake stuff I picked up when they ran a 50% off sale a year or two ago and I think I actually might have the same glass on one of the VFD modules GU256x64D-7000, so if it dies, I've got a VFD glass I can try down the road.

Just for fun I hooked up the logic analyzer to it to see if I could discern the signal.  These are chip in glass "CIG", but they are not full high level driver in glass.  The CIG is meant to just lower the pin count so it is really some shift registers and grid drivers.  Just enough to reduce pin count, but not more than that.  Noritake has a helpful document on this here:

https://www.noritake-elec.com/display/cig_driver_vfd.htm

But, they actually go further than that - they combined the grid and data spi into a single spi.  The first 256 bits are data, and the final 64 bits are grid.

From GU256X64D

Code: [Select]

pin	name	description
6	HV	60v
7	gnd
8	gnd
9	vcc	3.3v
10	sig1	4.57k, positive pulse 16us		blanking
11	sig2	4.57k, positive pulse 1us		latch
12	sig3	2.25k, square wave
13	gnd
14	nc	data out?, 800ns wide pulses (1.25MHz clock)
15	nc	data out?, 500ns wide pulses (2MHz clock)
16	sig4	data in
17	sig5	clock
18	sigA	data or clock ?
19	sigA	
20	sigA	
21	sigA	
22	nc	data out?

An entire frame is 14.21 ms so refresh rate is 70.3729.  I wonder if Fluke may be running it slower in their implementation of driving it because out of the corner of my eye I can see it updating sometimes.

So, I exported the data out of the Saleae and wrote a quick C program that converts the captured values to an image to see if I could do it.  It was a bit perplexing as the order of the bits changes between columns.  It has 64 four bit columns.  So a byte is two rows tall.  First it is 7654 with 3210 under it, and then it is 4567 with 0123 under it.  See the Noritake doc, probably has to do with overlapping grid scan.

The bottom line though is that with only a few pins and a microcontroller, one could convert the 256x64 bitmap display output to practically anything.  OLED, LCD, maybe even composite for precision meter meets old school TV output...  Might be a fun project down the road for 8845/8846's with bad displays.

The PNG is from a GU256X64D test screen:

[dr.diesel]

Even if you set the display to say around ~70%, I bet you get 20+ years of acceptable lab use.

By then the 3459A 12.5 digit will be out, sold exclusively at the prestigious Taco Bell T&M division.

 O0

[alank2]

You get low/med/high and it doesn't look like high is full power so I'll bet Fluke has tweaked the firmware in an attempt to make the display last as long as possible.  I read somewhere here that it is supposed to default to "med", but I think the last one I got arrived on low.  We'll see how long it lasts...

[XFDDesign]

Well guys, I've come to the conclusion that the 8845A is the 6.5 digit meter _I can afford_.  Zoro has 30% off today (still going) and that brought the price to $756 shipped.  On top of that they have a gift promo going where you can get an ipod touch or fluke 116.  So ... I ordered it again.  Hopefully this one won't have the 1 Hz buzzing noise, and at this price, I'll live with the display.  I would have preferred the 34461A, but it is $300 more and no gift.

Weren't you disappointed in the display, even neglecting the flicker issue?

[alank2]

Weren't you disappointed in the display, even neglecting the flicker issue?

Yep, it comes down to what is affordable.  I got it for $54 less this time as well.  I would have preferred the keysight 34461A's TFT, but I can't see anywhere to get it for less than $1050 shipped, this was $756 shipped and I will get a gift from Fluke for $150-$250, bring it down to $500-$600.  At that price I can lower my "display" expectations a bit and see how it holds up.

[XFDDesign]

Yep, it comes down to what is affordable.  I got it for $54 less this time as well.  I would have preferred the keysight 34461A's TFT, but I can't see anywhere to get it for less than $1050 shipped, this was $756 shipped and I will get a gift from Fluke for $150-$250, bring it down to $500-$600.  At that price I can lower my "display" expectations a bit and see how it holds up.

If display attractiveness is such a high priority, you're precisely saying you're compromising on your #1 value. How long will it take you to save up the extra cash and get something pretty and makes you happy? As it stands, you've already stated your dislike of the display - so you're going to be dissatisfied from this point forward over saving ~25%.

Consider, "I want to buy a 6.5 digit meter. I don't have $1,300, so I'll spend $1,000 for a 4.5 digit meter instead." It's very literally defeating the original point. 

[alank2]

My primary concern really isn't the attractiveness, but longevity.  I don't want to spend on a piece of equipment that is going to not be usable in a short period of time if i can help it.  5 years from now if it dies, will it become useless or can I make it workable without pouring a ton of money in to a part?  I'm more satisfied now that I can replace it with another type of display if I had to...  Perhaps my expectations are less now...  This $$$ is at the very upper limit of what I want to spend, the additional 30-40% for the 34461a defeats it.

[alank2]

The second 8845A arrived today - curiously between the last one and this one, they changed the box!  The first one came in an odd contraption where the meter was pressed between two plastic sheets held in the center of the box.  The new one is a smaller box and uses a traditional type of foams on each end of the meter.  No plastic bag.

This one does seem to have a better display than the first one.  The test screen does not show burn in of any kind yet and it seems a little bit brighter even on low.

I've attached a spreadsheet that compares both of the calibration reports for anyone who wants to see the calibration info.

It does make the same 1 Hz ticking noise the first one did.  More experimenting shows that it happens in certain modes like the frequency/period/ACV modes.

BTW, one nice thing I noticed with both units is that they include the RS232 to USB cable - something Fluke says is $150.  Most of the Fluke documentation says this won't be included, but their website shows that it is included.

[tautech]

It does make the same 1 Hz ticking noise the first one did.  More experimenting shows that it happens in certain modes like the frequency/period/ACV modes.

Wouldn't that be a relay switching in dual measurement mode?
Surely you can turn that off and have it only in single measurement mode or can you?

I know with the SDM3055 Siglent dual measurements are not available for all measurement types and in single measure mode it only switches for range changes.
In dual it switches at ~1Hz.

[eas]

The second 8845A arrived today - curiously between the last one and this one, they changed the box!  The first one came in an odd contraption where the meter was pressed between two plastic sheets held in the center of the box.

Sounds like they reused a box designed for equipment repair returns. Those things can be shipped flat to the customer, who then assembles them and returns them with the equipment to be serviced.

[alank2]

Wouldn't that be a relay switching in dual measurement mode?
Surely you can turn that off and have it only in single measurement mode or can you?

It isn't a relay firing, more of a buzz buzz buzz.  Just in regular AC/frequency/period mode.  Perhaps someone else with an 8845 or 8845 can see if theirs does it.  Both of the ones I've seen do so I'm not going to worry about it.

[georges80]

Yeah, on frequency I can here a quick buzz, buzz, buzz... if I tilt my head/ear to it from a few inches away and have to listen for it to even notice it in a quiet room - at least with my aging ears. If it had even a quiet fan you would never know.

cheers,
george.

[alank2]

Yeah, on frequency I can here a quick buzz, buzz, buzz... if I tilt my head/ear to it from a few inches away and have to listen for it to even notice it in a quiet room - at least with my aging ears. If it had even a quiet fan you would never know.

Yep, that is it all right.

[Deathwish]

Wouldn't that be a relay switching in dual measurement mode?
Surely you can turn that off and have it only in single measurement mode or can you?

It isn't a relay firing, more of a buzz buzz buzz.  Just in regular AC/frequency/period mode.  Perhaps someone else with an 8845 or 8845 can see if theirs does it.  Both of the ones I've seen do so I'm not going to worry about it.

You lucky !, it comes with a free inbuilt insect UV zapper