EEVblog 1378 - NEW Uni-T UT61E+ Multimeter

[EEVblog]

Is the new Uni-T UT61E+ Multimeter still the bang-per-buck king the existing UT61-E was? How does it compare? Is the increased cost worth it?


https://s.click.aliexpress.com/e/_AaRaJS
https://s.click.aliexpress.com/e/_9foaZO
And what about the ANENG AM870 at half the price?
https://s.click.aliexpress.com/e/_AFiPjA

[SeanB]

Nice meter, though 20A DC measurement, with a 10A fuse...... Guess it is the same current shunt, just with the "30 seconds maximum" there to prevent you blowing the fuse too often.

Waiting for Joe to blow it up, and if it will survive the grill starter lowest energy test that he has. My bets are it might just barely pass, but will fail on the higher energy tests. But at least they spent the 30c and added in the 3 MOV's to it.

Looking at the high resolution photoset, soldering on the input side not the best, with the lovely splatter on the input side.

https://www.flickr.com/photos/eevblog/albums/72157718441411852/with/50980777783/

Nice photos there Dave, that cardboard box is doing great work!

[Wytnucls]

Extra cost gives you some extra features:

AC+DC Volt
Min/Max
VFD
hFE
Backlight
Latched continuity
NCV

[HKJ]

The safety of the old UT61E depended on model, there was a EU model with better safety.
I wonder if the new model has same issue in the current ranges as the old model, the burden voltage is a bit high in the high uA and mA range.

[MikeK]

Is it a problem that the new one won't accept a standard BNC female to dual banana male for mA?

[madires]

10 or 15 bucks more would be fine, but 30 is simply too much for the improvements. And I fully agree that the hFE measurement is a complete waste and should be replaced with a temperature measurement.

[Brumby]

Get rid of that chunky transistor adapter and save a few bucks right off the bat!

[CChin254]

Design Wins:

IC Identification:



The other version (UT61E+) contains a AD737 RMS/DC Converter instead of the Cyrustek Co. solution used in the UT61E+).

[jivaei]

One other thing to note is that the old UT61E is hardwired to not auto shutoff, presumably for RS232. The UT61E+ should support auto shutoff as it can detect if the RS232 receiver is inserted.

[Fungus]

Where's the 10MOhm input resistor chain? I can't see it.

Definitely give the Aneng 870 a spin but get some of these super needle-sharp gold probes to go with it:

https://es.aliexpress.com/item/33006553337.html

:-)

The only thing I see that this has going for it over the Aneng is USB interface and faster autorange. And a better stand.

Wasting a whole switch position on hFE and an NCV function that barely works is unforgivable. My Aneng 870 can detect a live wire from about 10cm away (4 inches).

Edit: That's not quite true. It can detect a pug board with 4 plugs in it from about 10cm away. A single unloaded mains cable makes it beep at 3-4cm depending on the angle of the cable.

[HKJ]

Where's the 10MOhm input resistor chain? I can't see it.

In the black box, together with the other input divider resistors.

[Fungus]

Where's the 10MOhm input resistor chain? I can't see it.

In the black box, together with the other input divider resistors.

The old version has MELFs and a black box.

[floobydust]

Why aren't we calling out fake regulatory claims, especially when they are obvious?
The DMM is the usual fail - 250VAC fuses (with lots of room for bigger ones) - Intertek would not give 61010 approvals beyond that, unless they were sleeping or bribed. How did this achieve claimed 600V or 1,000V certification? I remember only one or two of the Uni-T UT61 models had a legit certificate and the others did not. One reason to stretch the truth and cling to an old model number.

You can't put two PTC thermistors in series and expect equal sharing. One always heats up first and then takes the brunt of the HV whilst the other one sleeps. It's like two polyfuses in series, all the voltage can appear across one when tripped. So I would check a single PTC is rated for the overload voltage expected.

%Hz is plastered at seven places on the front labels, enough already.

[mariush]

My guess is that they didn't want to make a custom dongle bit just for this series, so they added the hFe feature to support the transistor bits on the dongle.

I didn't see it mentioned, but the another plus for the new meter is the 3 updates/s  versus 2 updates/s for the old model.

The 9mA power consumption is a bit weird, considering the old regular ut61e consumed much less, and worked with very low voltages... was showing low voltage at 5.6v but worked with around 3v

But hey, plenty of room to add a lithium "pouch" style battery and a basic charging circuit in that square.

Also have to wonder, considering the multimeter chip advertises 30000 count, maybe it's possible to modify some parameters or code to make the meter stay within a range up to 29999 or something like that.

The IC also advertises running at 3v DC so maybe you don't even need 4 batteries, or using a single 3.7-4.2v lithium battery would be very easy to use.

The datasheet is available on Cyrustek website: http://www.cyrustek.com.tw/spec/ES232.pdf

It has info about the serial comunication between IC and mpu, along with the commands and how to decode everything, so you can

[Fungus]

Why aren't we calling out fake regulatory claims, especially when they are obvious?
The DMM is the usual fail - 250VAC fuses (with lots of room for bigger ones) - Intertek would not give 61010 approvals beyond that, unless they were sleeping or bribed.

Is Intertek certifying this one?

There's a UT161E which is certified but it costs a lot more:

https://www.batronix.com/shop/multimeter/UNI-T-UT161E.html

I wonder what's inside? Could the 61E be converted to a 161E? It looks like there's holes on the PCB that would would let you desolder the fuse holders and move them further apart to accept 1000V fuses.

Also interesting is that the MOVs are labelled "SG1", "SG2"...  SG is usually "Spark Gap".

[thm_w]

Wasting a whole switch position on hFE and an NCV function that barely works is unforgivable. My Aneng 870 can detect a live wire from about 10cm away (4 inches).

Edit: That's not quite true. It can detect a pug board with 4 plugs in it from about 10cm away. A single unloaded mains cable makes it beep at 3-4cm depending on the angle of the cable.

Its dangerous, you create a false sense of security that the wire is not live, start working on it and get zapped.
You want a relatively sensitive NCV if you are doing any sort of actual electrical work (eg drilling in walls), the ones in these meters is just trash.

They wouldn't do it but: get rid of NCV, get rid of HFE plugin, get rid of the USB adapter (sell it as an optional extra). This would bring the price down a bit. But I suspect a lot of sales are made from these useless "features".

[floobydust]

Why aren't we calling out fake regulatory claims, especially when they are obvious?
The DMM is the usual fail - 250VAC fuses (with lots of room for bigger ones) - Intertek would not give 61010 approvals beyond that, unless they were sleeping or bribed.

Is Intertek certifying this one? [...]

The prior UT61E is a two-faced dog. I see Uni-T has obtained approvals for the UT61E under TÜV Rheinland GS Mark, then sells versions with stripped out protection components (MOV's). They likely carried over that 61010 certificate to other agencies such as Intertek.

Intertek ETL product certification database:
Company:  Uni-Trend Technology (China) Co., Ltd. - Dongguan, Guangdong CHINA
Trade Name(s): BESANTEK, AMPROBE, EXTECH INSTRUMENTS, Minipa, UNI-T, actron, BOSCH.

UT61A, UT61B, UT61C, UT61D, UT61E are listed but not the UT61E+.

edit: I expect these larger Asian test equipment manufacturers to have some integrity and not make fake 61010 claims about their multimeters.
Why else would a BBQ lighter kill, why have 250V fuses with 1,000V claims, why depopulate the MOV's for everywhere but Germany?
Although, Uni-T's 61010 test reports are quite a bit how ya doin' and the certifier could be glossing over the details.
Irregardless, it's just shady and aren't we tired of this?

[Fungus]

Irregardless, it's just shady and aren't we tired of this?

Yep. Cheap meters have their place but fake CAT ratings could put people's lives at risk. Not everybody reads EEVBLOG forums.

[SilverSolder]

[...]
why depopulate the MOV's for everywhere but Germany?
Although, Uni-T's 61010 test reports are quite a bit how ya doin' and the certifier could be glossing over the details.
Irregardless, it's just shady and aren't we tired of this?

Isn't this down to how much "teeth" the national regulatory agencies have?  Write to your local representative?

[floobydust]

It's possible Germany is strict and bans imports of products with no safety approvals/certificate, unlike all the too nice nations of the world.
I think it's more affectionately known as the "Golden Sample". The one that looks great, lures customers and passes regulatory. Then you swap in the cheaper version.
The old UT61E MOV's are USD $0.08/1k for a set of three. So in the bait and switch they saved pennies. I don't know of any other company playing games like that, they should grow up.

For the UT61E+ my beef is no approvals, the word 'Electrician' on the faceplate, they kept the allocated room for larger fuses (like the UT61E) but decided 250V is fine. Why bother with a plastic guard box around the fuse if you're only expecting 250V there? It makes no sense. I feel better when the meters have actually been tested to their rated 1,000V to prove the pcb clearances are correctly done.

[Fungus]

Why bother with a plastic guard box around the fuse if you're only expecting 250V there? It makes no sense. I feel better when the meters have actually been tested to their rated 1,000V to prove the pcb clearances are correctly done.

...or make nice meters but put real ratings on them.

Even so, joe has killed many UNi-Ts con a grill starter. I still want some robustness even on a meter that isn't industrial-strength CAT rated.

[Kleinstein]

The regulations / customs should be similar in the whole EU - so it would not only be Germany to get a different version. German customs may be a little more strict in inforcing the regulations than some other EU countries. This sometimes can be a problem ordering parts from China that miss the CE stamp. There were different versions in the EU. I don't remember much better protection, but a lower, more realistic CAT rating. The the EU version may end up with a 250 v CAT 2 or similar. At least they note the limited fuse Voltage rating and don't keep it secret.

There is nothing really wrong with a CAT 2 meter if labled correctly. There is a market for these at the lower cost end.

The transistor tester is probably not worth the weight - it has some interresting lookign contacts to put SMD transistors inside. Proper SOT23 test sockets are kind of expensive.
Still one can get a much better transistor tester for some $20 or so.

For the battery compartment, it may be interesting to see if it is water tight.
Instead of HFE function they should add a leaking battery warning.

[EEVblog]

Why bother with a plastic guard box around the fuse if you're only expecting 250V there? It makes no sense. I feel better when the meters have actually been tested to their rated 1,000V to prove the pcb clearances are correctly done.

The plastic guieard is there for the fuse to switch contact voltage clearance. That's a different failure mode to the fuse break voltage rating.

[floobydust]

After the fuse has cleared, it has hazardous live on one end and between both ends.  The plastic guard is on the (blown) fuse's hot side. With a 250V fuse, that node would go up to its breakage voltage rating of 250V or 1kV, which seems low to warrant building a guard there. But the 3D of the rotary switch I guess you'd have to see or test.
Let's say the guard might be for the other direction, no arc from rotary switch to the fuse. But again the guard is at only one end of the fuse, ignores the other end, so that's not the design intent. The MOV's are supposed to limit the voltage at the rotary switch though. The PTC's are considered highest voltage, so the trace running off from PTC4 to the rotary switch is likely a disaster.

The point of a formal regulatory assessment is they measure creepage and clearances, and test with high voltage to verify a safe PCB/product design. Every PCB designer has the best intentions yet they do make mistakes.

[Kleinstein]

The other / non shielded end of the fuse has a link to the main part of the circuit / rotary switch anyway. So there is no need to also have a shield or guard at that end of the fuse.

The line running from PTC4 to the rotary switch may be clamped with some device - it could be some clamping diode or similar. We don't know the resistance of the PTCs - if they are relative high resistance to start with, they may be oK without an extra series resistor.