A multi meter is nothing more than a tool to get the job done, are you hindered by these tools in getting the job done?
If not than these tools are just fine! :-+
eg. If I was an electrician working with mains electricity every day then I wouldn't use either of those, for safety reasons.
eg. If I was an electrician working with mains electricity every day then I wouldn't use either of those, for safety reasons.I have to ask why? As long as they actually comply with the relevant standard, and not fudging their testing, the UT61D is CAT. III 1000V, CAT.IV 600V. So comparable with Fluke, Keysight et al.
It's a shame really. Uni-T UT61/E has a really nice form factor and the screen on it is top notch, very easy to see and read.
As far as "accuracy" goes, one of the best ways to be confident about accuracy is to own two or more meters and regularly switch between them. If you do this you'll soon see if a meter is misbehaving or not.
I'd get a Fluke 101 if I regularly worked with mains electricity. Only $42 delivered and one of the safest meters available at any price.No you wouldn't. You would use a Fluke 87, just like the rest of your co-workers, unless you wanted to be the butt of their jokes.
I'd get a Fluke 101 if I regularly worked with mains electricity. Only $42 delivered and one of the safest meters available at any price.No you wouldn't. You would use a Fluke 87, just like the rest of your co-workers, unless you wanted to be the butt of their jokes.
Don't confuse safety with Joe's 'ruggedness'. The 101 is only rated 600V CAT III.
It's a shame really. Uni-T UT61/E has a really nice form factor and the screen on it is top notch, very easy to see and read.
It measures a lot of different things, too, and is quite accurate.
But for the accuracy, I am not convinced. My UT61E measures 10.000 V from a breadboarded REF102 :-+. But my three 0.005% resistors are off. The readings are within the UT61E spec (0.5% +10 counts), but the readings are far from being close to spot on (up to 16 counts off when measuring a 1 K 0.005% resistor).
Uni-T is famous for not complying with the CAT ratings printed on the front.
Many of their meters also come in different internal variations. Same model number, identical on the outside but some have glass fuses instead of ceramics, some are missing PTCs and MOVs, etc, etc. You never know what you're getting.
There's many many examples of these problems on EEVBLOG, two minutes with google will convince you. Dave even did a video after he bought one for hs own personal use then was horrified after he opened it:
QuoteBut for the accuracy, I am not convinced. My UT61E measures 10.000 V from a breadboarded REF102 :-+. But my three 0.005% resistors are off. The readings are within the UT61E spec (0.5% +10 counts), but the readings are far from being close to spot on (up to 16 counts off when measuring a 1 K 0.005% resistor).
Use better multimeter probes or clean the probe tips with some isopropyl alcohol and some abrasive material and use the REL button.
If I was an electrician working with mains electricity every day then I wouldn't use one of those, for safety reasons. :)
If I was an electrician working with mains electricity every day then I wouldn't use one of those, for safety reasons. :)
i would.
lets just put the fluke / brymen sales team to one side for a moment.
an electrician will never read current with a shunt - it's dangerous - they would use an induction coil or clamp meter.
so the fuses are irrelevent.
and mains is going to be 110 - 240v or worst case 440v.
so no amount of mov's is going to make any difference because they are rated at over 200% of your maximum working voltage.
I agree that the UT61E form factor and functionalities are good.
But for the accuracy, I am not convinced.
I had one bought at a sale, its crap. Open it u and you`d see. The one I had stopped working after about 2 years just sitting in storage, in room (so no dust or water). Input protection on these is hillarious, if a fuse blows they appear to have zero capability to protect you (look at the case), input jacks are...well.
That said, so far my badly (total understatement) chopped up UT61E performs well. It has provided me with several hours of entertainment value and I suspect will continue to do so if I think of something else to do with it.
That was a conservative estimate!
I'd get a Fluke 101 if I regularly worked with mains electricity. Only $42 delivered and one of the safest meters available at any price.No you wouldn't. You would use a Fluke 87, just like the rest of your co-workers, unless you wanted to be the butt of their jokes.
Don't confuse safety with Joe's 'ruggedness'. The 101 is only rated 600V CAT III.
I'm not familiar with Poland's general attitude towards safety, but the meter should at least be rated CAT IV, with a recognized safety agency listing.
In an industrial environment, meters are provided by the company and are usually of high quality, mostly for their reliability, ruggedness and reputation in case of accident litigation.
Indoors only: CAT III is sufficient.
Where I live, a lot of electrical cabling is on the outside of the house: Garden lights, water pumps, pool pumps, air conditioning units. Often, 'house' electricians have to deal with those too.
I'm not familiar with Poland's general attitude towards safety, but the meter should at least be rated CAT IV, with a recognized safety agency listing.
In an industrial environment, meters are provided by the company and are usually of high quality, mostly for their reliability, ruggedness and reputation in case of accident litigation.
Cat 4 volt sticks, gloves, glasses and rubber boots anyone ? >:D
I'm not sure what your rubber boots measure if they're considered viable for CAT IV;)
They're okay (meaning you'll remember not to do this again, but you won't die) in case of 230V RMS. Not sure about these lightning transients. I don't advocate grabbing mains conductor whilst in rubber heels and waiting till lightning strike.I'm not sure what your rubber boots measure if they're considered viable for CAT IV;)
High rubber heels? ^-^
I'm not sure what your rubber boots measure if they're considered viable for CAT IV;)
High rubber heels? ^-^
Cat 4 volt sticks, gloves, glasses and rubber boots anyone ? >:D
I'm not sure what your rubber boots measure if they're considered viable for CAT IV;)
Cat 4 volt sticks, gloves, glasses and rubber boots anyone ? >:D
I'm not sure what your rubber boots measure if they're considered viable for CAT IV;)
With warm socks (and heavy duty odour eaters) they are a better bet to survive confirming voltage present outdoors,
than just bare feet or sandles standing on wet concrete, wielding a supposedly 'safer' Fluke meter ...or Uni-T 'cross your fingers' meter ;D
which I don't do anyway, if I observe dark clouds at a distance (lazy lightning can find another short path to earth, I don't need any more HV tingles)
Where I live, a lot of electrical cabling is on the outside of the house: Garden lights, water pumps, pool pumps, air conditioning units. Often, 'house' electricians have to deal with those too.
If they are powered by power derived from an indoor distribution panel, then why they pose CAT4 hazard?
Of course, this is taking a risk since CAT3 doesn't require so high voltage transient seen by induced lightning, but let's face it, how big a chance will you be hit by an induced lightning over just a few meters of cable? Induced lightning protection is needed for long distance outdoor wires due to longer length, usually a few meters from service drop to your house. But for just a few meters from your panel to AC unit? I don't think there is a big chance.
They pose CAT4 hazard, because person using a meter isn't qualified to discriminate between "lightning more than few kilometers away" and "oh shit". Apparently it's safe to operate your phone charger with 0.5mm paper & homeopathic enamel between your USB charger primary and secondary during thunderstorm whilst sitting in your shed connected via outdoor wiring, having your feet massaged via foot-massage bath, but a chunky multimeter (even DT830 Harbor Freight freebie is quite chunky in comparison) is a death trap.
Would yo also argue that your car doesn't need airbags because you're a perfect driver and the roads around your house are fine?Nope, that's why things like circuit breakers and GFID/RCDs exist on low voltage.
c) Joe has exploded several meters in his thread. He doesn't test on the current ranges.And working at a substation 15kV -> 400V I haven't exploded any.
QuoteWould yo also argue that your car doesn't need airbags because you're a perfect driver and the roads around your house are fine?Nope, that's why things like circuit breakers and GFID/RCDs exist on low voltage.
Quotec) Joe has exploded several meters in his thread. He doesn't test on the current ranges.And working at a substation 15kV -> 400V I haven't exploded any.
They pose CAT4 hazard, because person using a meter isn't qualified to discriminate between "lightning more than few kilometers away" and "oh shit". Apparently it's safe to operate your phone charger with 0.5mm paper & homeopathic enamel between your USB charger primary and secondary during thunderstorm whilst sitting in your shed connected via outdoor wiring, having your feet massaged via foot-massage bath, but a chunky multimeter (even DT830 Harbor Freight freebie is quite chunky in comparison) is a death trap.
I am wondering why are folks defaulting to thinking that I would be doing high voltage stuff...
For me there is a voltage cap of 400Vrms on my projects (highest voltage in a mains-rated PFC circuit).
I am wondering why are folks defaulting to thinking that I would be doing high voltage stuff...
Who said "high voltage"? I think everybody's talking about mains electricity.For me there is a voltage cap of 400Vrms on my projects (highest voltage in a mains-rated PFC circuit).
I was about to say "don't use a Uni-T for that" then I remembered you've been using a DT890. A Uni-T is a big step up in safety.
For everyone recommending a Fluke: check the price. A UT61E in western market sells at $50, while a used Fluke 87V is only $220, but in China, UT61E only sells at $25, and a Fluke 87V sells at at least $285.
Now, instead of 4.4x the price, it is 11.4x the price difference.
If you're over the Uni-Too good to be true thing
I will be looking for a Fluke. Not the 17B+...although why not.
BTW, I'm never a fan of F15B+ as it doesn't have uA measurement
Hi gents Electro Detextive...yeah I have a qty of old Jaycar and DSE multimeters. Funny enough my old digetech QM-1525 holds better accuracy than the UniT.
I will have to get a cheap precision reference for now but I will be looking for a Fluke. Not the 17B+...although why not. Yes it was for China market but hey...the price. :-+
... you can buy a DMM check and calibrate your UT61E every year. It doesn't need fancy special software to calibrate, just trimmers.
...
Is there a calibration procedure available for the UT61E?
:)
No official ones, but you can play with pots randomly and see which does what.
Take a picture before touching anything so that you can fallback.
Here is an unofficial one: http://gushh.net/blog/ut61e-calibration/ (http://gushh.net/blog/ut61e-calibration/)
... you can buy a DMM check and calibrate your UT61E every year. It doesn't need fancy special software to calibrate, just trimmers.
...
Is there a calibration procedure available for the UT61E?
:)
i dont know why people keep talking about fluke meters like they last forever,
a friend has a few 77's
all needed new zebrastrip and one needed a new display glass.
you calibrate it by throwing it against a concrete wall, and purchasing a fluke. :D
just kidding...
you can usually find a data sheet on a particular dmm chipset and use it to find out what the various trimmers adjust.
I replaced a few zebra strips on them as well, but they were 15-20 years old or something. I have an old 87 (non V) that's probably 20 years old now, and still in spec.i dont know why people keep talking about fluke meters like they last forever,
a friend has a few 77's
all needed new zebrastrip and one needed a new display glass.
Flukes are nothing special, just like any other decent meter they last as long as you take care of them, and also depends on temperature and environmental conditions. I've replaced several zebra strips and couple LCD's on Flukes over the years. Also I've had a couple 80 series with brittle shit plastic with broken clips and standoffs. Fluke is somewhat overrated in my opinion, it's just another meter.
"2.498"
"4.998"
"7.497"
"9.996""2.50047"
"5.00087"
"7.50063"
"10.00027"i suspect it's not "drift" but being bumped around causing the multi-turn preset to shift a bit.It's likely mechanical stress related as you put it.
those things arent the most stable devices.
i suspect it's not "drift" but being bumped around causing the multi-turn preset to shift a bit.
those things arent the most stable devices.
Is there a calibration procedure available for the UT61E?
:)
Urrrrgggghhh...my UT61E is way out on voltage. 9.1V @ 10V in. Ok granted I do not have a precision reference just a PSU with inbuilt meter, but the other meters are within .05 ~ .03V of 10V!
Ahh huh...just touched the voltage cal pot...it jumped big jump back to 9.99...volts on 10V in.
Now varying the wiper up/dwn it appears ok and changes accordingly (linear fashion) but at first it jumped ....a lot. Possible pot issue?
Ahh huh...just touched the voltage cal pot...it jumped big jump back to 9.99...volts on 10V in.
Now varying the wiper up/dwn it appears ok and changes accordingly (linear fashion) but at first it jumped ....a lot. Possible pot issue?
Have a look at the solder joints holding it to the board before blaming the pot.
Ahh huh...just touched the voltage cal pot...it jumped big jump back to 9.99...volts on 10V in.
Now varying the wiper up/dwn it appears ok and changes accordingly (linear fashion) but at first it jumped ....a lot. Possible pot issue?
Have a look at the solder joints holding it to the board before blaming the pot.
+1, most of the cases I found are cold joins, just watch carefully if the solder is shiny or hazy (cold join).
Many thanks to all. I had noticed the meter getting really bad on accuracy in volts since the autumn cold weather arrived.
Hmmm its a $6 IC in Aust. Going to have to look at this. Noticed they have this IC in .1% and .05%! But the .05% is ~$6.
nah, they buy used fake ones on the black market... ;)Hmmm its a $6 IC in Aust. Going to have to look at this. Noticed they have this IC in .1% and .05%! But the .05% is ~$6.
and that's probably why it was not fitted - that's a lot of money in china!
I just imagine myself an electrician with a sadomaso rubber suit in a technical room >:D :-DD :palm:
They won't prevent the meter from exploding in your hand if you select the wrong range.That's why we don't use meters with possible low impedance path on high energy circuits unless we check twice or more we're on right range. No HRC fuse or CAT rating will help even on low voltage distribution line if you're near the transformer and something goes really wrong - I put my safety into considerations about other, more probable things, like knowing that if something goes wrong I won't fall down from the pole and have a head trauma (most electricity injures come not from an actual eletrical shock, but blunt trauma after you did nasty landing fom the ladder/whatever).
Quotec) Joe has exploded several meters in his thread. He doesn't test on the current ranges.And working at a substation 15kV -> 400V I haven't exploded any.
Just a question...modifying the Vref to an LT1790 hi precision...they don't explain (in the part pdf or above site) if they use 1% or better resistors and high precision caps?
I guess at least 1% would be required...or is this overkill.
For most people, a DMM is only used in an indoor environment where temperature is in a narrow range. Therefore, tempco can be ignored. In that case, 1% or 10% doesn't make any difference if there is a trimming pot.
......I tried to calibrate it via the inner voltage calibration trimmer and realized it is real crap ...if you turn it 360° there is no change..then another few degrees of rotation and the value suddenly changes a lot
I should replace it with a new bourns trimmer
That is exactly what I initially saw. Then winding the pot back and fourth...it started to give a more linear response. Quite odd like the wiper was stuck or not tracking correctly. Its keeping better voltage accuracy now though.
I tested my UNI-T 61E between 20°C and 36°C by leaving it on in a PS foam box with a incandescent lamp for a few hours, connecting it to an external voltage reference
In spite of what I expected the value displayed never changed, although it was lower than the value displayed by a better multimeter
I tried to calibrate it via the inner voltage calibration trimmer and realized it is real crap
if you turn it 360° there is no change
then another few degrees of rotation and the value suddenly changes a lot
I should replace it with a new bourns trimmer
I just wonder if the crappy trimmer variation with temperature casually compensates the variation of the multimeter reference :-//
I also noted my PCB layout is different to the PCB in the Vref mod. The layout on mine is different and there is no unused pads for an LT1790 etc
......I tried to calibrate it via the inner voltage calibration trimmer and realized it is real crap ...if you turn it 360° there is no change..then another few degrees of rotation and the value suddenly changes a lot
I should replace it with a new bourns trimmer
That is exactly what I initially saw. Then winding the pot back and fourth...it started to give a more linear response. Quite odd like the wiper was stuck or not tracking correctly. Its keeping better voltage accuracy now though.
I also noted my PCB layout is different to the PCB in the Vref mod. The layout on mine is different and there is no unused pads for an LT1790 etc
The Pot on mine is "X202" so a 2K ohm pot multi-turn. The cct diagrams show it to be 1K ohm
I tested my UNI-T 61E between 20°C and 36°C by leaving it on in a PS foam box with a incandescent lamp for a few hours, connecting it to an external voltage reference
In spite of what I expected the value displayed never changed, although it was lower than the value displayed by a better multimeter
I tried to calibrate it via the inner voltage calibration trimmer and realized it is real crap
if you turn it 360° there is no change
then another few degrees of rotation and the value suddenly changes a lot
I should replace it with a new bourns trimmer
I just wonder if the crappy trimmer variation with temperature casually compensates the variation of the multimeter reference :-//
I would expect for 16 degree you would see 5.125 uV/degC or 82uV. Basically 8 counts. For all I know you were in the DCV range. I did not save my data and tc may not be linear. After temperature compensating mine with a diode/resistor, tc was 0.625uV/degC.