Review: UNI-T UT61E digital multimeter

click works! i like the large picture :)

please leave the link (no delete). Very helpful!

looks like nice built quality!!

THANKS!

Given the weakness on current measurement are you aware of any meter for the same sort of money that would be better.

Don't need logging and already own an ancient and very battered Fluke 77(III).

Not really. I daily use I am using much more expensive meters (Fluke 179/189/289/8846A and MetraHit Energy), they do also have to be watched on the current ranges (But the are considerable better than UT61E). The best meter I have seen (For burden voltage) was a cheap meter with manual ranges and no fuses, but it did have other problems (That is no surprise).

I might review a few other DMM's, but I have not really decided it yet.

For truly GOOD current measurements, it's best to stop screwing around with regular DMM's at all. Get a current clamp meter - it has exactly ZERO burden voltage.

Even a really cheap current clamp meter will show MUCH more accurate real-world current measurements than any DMM with leads (thick or thin).
http://www.storeinfinity.com/mastech-ms2108a-4000-counts-ac-dc-current-clamp-meter.html

Personally, when I need a precise current measurement, I use an Agilent N2783B Current Clamp connected to an Agilent MSO7054B Oscilloscope, but that's way overkill for LED type current measurements. The <$40 current clamp above is more than adequate. Either way, measuring current with a leaded DMM or the voltage accross a shunt resistor (0.1 OHMS gives a 1 Volt burden voltage at 10Amps) is a very bad way to get real-world measurements from a system like an LED torch.

Damn fine review of that DMM though - for the (incredibly low) price, it's a nice unit. I love my Hioki 3801-50, but it's nowhere near that price point, and it's not "better enough" to justify the additional cost for the types of measurements necessary in our hobby. Even it sucks for current measurement because there is no such thing as a zero-burden leaded DMM in current mode.

PPtk

That is not correct. A current clamp is fine when measuring a couple of amps and up, but try measuring 10mA with a current clamp, where few can do that with any precision.

The 0.1 ohm resistor was not meant for 10A, only for below 1A. I do also say that in the review (It is in the mA range description).

I measure a couple of uA with a current clamp on a regular basis - Imon current on laser diodes. Just a pF of capacitance from a scope probe on these signals is more than enough to screw everything up. At this incredibly low level, the signal isn't terribly accurate, but its very repeatable and precise measurement to measurement. The current clamp I use is guaranteed accurate to 1% at anything over 10mA.

Agreed, I see that now. And yes, for measurements in the mA range, a shunt resistor is not a bad way to go - limited voltage drop at those levels.

Once again, really nice job on the review of the DMM. It really is a pretty nice unit for the cost.

PPtk

HKJ,

You mentioned the model has no back light, have you tried press and hold the yellow button? My cheaper UT61A has back light LCD.

I also found out that despite my model does not come with temperature measurement but if I were to turn the dial somewhere in between say mA and uA, I get temperature (most likely ambiance) reading!

Excellent detailed review HKJ. Thanks very much! Sticky'd.

Nice review, thanks. OK a clamp meter is new to me. I had to YouTube it. How do you measure a flashlights current using one?

What was the price of that clamp?


The manual explicit states that it has no backlight (and the switch does not work either).

HKJ, you made my day. Thanks

If memory serves, about $4000. It was added to the lab a long time ago though, so I might be off by a bit - my memory for unimportant things isn't very long..

PPtk

Nice review! I may have to grab one of these. Didn't know these were so darn cheap! I've got a pricey Agilent datalogging DMM, but could use one for basic voltage logging.

It's funny that the unit you reviewed seems more accurate than the more expensive UNI-T-UT70B (although this model has the temperature feature).

Kreisler why do you have to use multiple usernames on BLF?

I liked your first reply more. Wink

I ordered the UT-203 clamp meter from dealextreme. It is okay, but the zero is way off - about 1.5 amps. It has a 'rel' button than can be abused for zeroing however.

The zero is not really stable but it is possible to figure out tens of mA on it. Compared to a rather anonymous brand at work the zero offset is a bit better on that one (half an amp) but still not perfect.

The Uni-T readings match my normal multimeter pretty well though.

I posted that post after researching the price on eBay and a few other sites. I see $62 Shipped on eBay is the lowest price, but I would probably buy from a US seller @ $69.99.

i did 2 amperage measurement sessions (tailcap readings: 10440 on Hi, 10440 on Med) and saved the 2 XLS files, then opened them with Excel2010, deleted the unnecessary columns (DC/AC, Unit, AUTO) and some rows (beginning and end measurements). i copied the Med-amperage (see "D") measurements to the spreadsheet of the Hi-amperage measurements (see "C"), and finally selected both columns and let Excel2010 produce a line graph:

the 2 line graphs look nice (and we can even see the down-step from Hi to Hi-2 after 7mins; f e n i x l d 0 1 r 4 : unregulated driver with 10440's so the down-step must be a time-controlled feature!!) but the x-axis looks wrong:

  • it should begin with 0.0 (unit time: seconds), and not with "1" as shown
  • the time difference between 2 neighboring data points is 0.5sec (the runtime of 10440-Med is ~30mins, and not the double "3601" as shown)
  • the ticks should be 1 tick per 60 seconds (=1 tick per minute)

I will also try to visualize the data with other graphing software (Wolfram, Origin) but if someone is proficient in Excel and knows how to quickly get my x-axis "corrected", then please shoot me. Obviously i am not proficient in using Excel at all

Thanks for some concrete Excel2007/2010 steps ..

The usual curve in Excel is not a x-y chart, but each value fills one position. If you have a entry at regular time intervals (Like each second), you can just calculate a column with time in second or minutes from start and the use it for "Category" labels. You will also need to edit the axis and define how often to show a value (Like only show 1 in 30 values). This is the method I uses for my runtime charts in my flashlight reviews.

The other solution is to select a real x-y chart, you have to open the full chart type selection to find it (It is called something with X Y). The again you need to calculate a time column and use it as the X value, but this time you do not need regular time intervals.

Hi HKJ, thanks for the tip with X-Y charts. Will try to figure it out now with my Excel2010. At the same time i am downloading Origin. It's easy to generate a 40mins time column with Wolfram but it's not installed on my system.

Looks like Excel isnt the most helpful here..

EDIT: another problem in Excel (or in combination with other software) is the interpretation of comma "," and decimal point ".", argh!!

EDIT2: X-Y charts: Excel returns an error because of some number of rows limitation (255 rows) or freezes. d*mn it. Excel is not recommendable at all if one has to manipulate or visualize thousands of data points!! :(