Handheld meter robustness testing

[PushUp]

Interesting (or boring fits better), that Benning seems to switch from Appa to Brymen with its upcoming "High-End-Multimeter BENNING MM 7-2", which seems to be a further "Brymen 78X"? clone with a slightly different display arrangement, but same specs...same test leads...same type-k...

Why should you pay 325 Euro for this DMM, when any Brymen is that much cheaper? I don't get it, because I don't think, that they managed to improve the clonky rotary knob or the useless backlight-timer...but we will see at the end of 2022-07, when it should be available:






...at the moment only on the german website - not yet in EN...

https://www.benning.de/produkte/pruef-und-messtechnik/digital-multimeter/high-end-multimeter-mm-7-2.html


PDF-Manual in EN:

https://www.benning.de/produkte/pruef-und-messtechnik/digital-multimeter/high-end-multimeter-mm-7-2.html?sbd=GBR&file=files/benning/global_content/downloads/instruction_manuals/benning_mm_7_2_instruction_manual_en.pdf&cid=134224


Cheers! 

[EEVblog]

Interesting (or boring fits better), that Benning seems to switch from Appa to Brymen with its upcoming "High-End-Multimeter BENNING MM 7-2", which seems to be a further "Brymen 78X"? clone with a slightly different display arrangement, but same specs...same test leads...same type-k...

Interesting, didn't know there was this variant. The LCD is very different to the 78x series.

[joeqsmith]

The KeySight arrived.  I ended up with a UT1282A (higher end version).   Supply chains are a total crap shoot.   

As always, if there's any non-destructive tests you would like to see before I run it, just let me know.

[bdunham7]

As always, if there's any non-destructive tests you would like to see before I run it, just let me know.

How about actual measured input impedance on all the AC and DC ranges?

[floobydust]

Suggesting that GDTs are not as good as MOV for this application is based on ignorance.  [...]

The ignorance is follow through current, which you do not include. Mains plus transients superimposed is a disaster with anything that crowbars such as GDT.
Fluke started with GDT and changed to MOV's, Brymen would have ditched the large MOV's long ago if they were practical.

[nightfire]

Why should you pay 325 Euro for this DMM, when any Brymen is that much cheaper? I don't get it, because I don't think, that they managed to improve the clonky rotary knob or the useless backlight-timer...but we will see at the end of 2022-07, when it should be available:

There are several reasons to go for Benning, when you are in germany:
- Distribution channel: Maybe the standard distribution channel where you always buy your stuff at carries this DMM, and you do not have to go to Welectron for a brymen
- Brymen= Whats that? Never heard of- and Benning, reputable brand (Duspol etc.) on the german market, so lets go this route
- Service and calibration from a german company, so that the beloved papertrail can be produced
- User manual in german (Users of Benning branded products are mostly electricians, so english knowledge is not always perfect)

[joeqsmith]

Suggesting that GDTs are not as good as MOV for this application is based on ignorance.  [...]

The ignorance is follow through current, which you do not include. Mains plus transients superimposed is a disaster with anything that crowbars such as GDT.
Fluke started with GDT and changed to MOV's, Brymen would have ditched the large MOV's long ago if they were practical.

"Application" is in context to this thread.   Not being aware of what this thread is about is ignorance.  While it's been covered many times over the last several years, suggesting my testing has anything to do with AC line testing or the safety standards is stupid.     

I understand you want to talk about disasters rather than robustness.  Failing to understand that the clamps (MOVs, GDTs) sit behind a large PTC and surge rated resistor, ignorance.    Every now and then people do comment about clamping the line.   Consider that the PTC and resistor will be over 2k ohms when cold.  My light bulbs present more of a load.    Of course the load my bulbs present are fairly constant when compared with a PTC.   Consider also that some of the meter's circuits will conduct far below where the GDTs or MOVs will come into play.

[Fungus]

MOVs are boring. GDTs are pretty, you can see them doing their thing.   

[bd139]

You do realise you’re not supposed to use them as indicators? 

Reminds me of that BM22s I was using to check HV with. It got backlit. Still works fine!

[Fungus]

That's got me thinking. I've never made a GDT clock...

How much voltage will I need to make the display nice and visible?

[bd139]

I'd buy a GDT clock.

May have to turn it off when I want to use the WiFi though 

[2N3055]

I'd buy a GDT clock.

May have to turn it off when I want to use the WiFi though 

Yeah you could call it a radio clock...

[floobydust]

I have only one GDT with a clear glass case, all others are ceramic with no glow joy. It's a 90V (neon) part and a bit flat for a clock.
Tried a NE-2 but it exploded.

[joeqsmith]

I have some free time and plan to start looking at the Keysight U1282A.   There have been several reviews for this meter already, including my own where we take a look at the front end design.   If there is something specifically you would like to see, now is the time to ask.  The last Keysight meter I damaged was not repairable and I don't have a lot of confidence in this meter going into it. 

[Fungus]

 

[rsjsouza]

Thanks for linking my video, despite being in Kling... *ahem* portuguese; I don't even remember what I said and tested on it, but I recall I didn't open it (it was still in warranty).

I look forward for your review and tests. It still ticks valiantly on my bench despite some mishaps in medium voltage.

[joeqsmith]

Thanks for linking my video, despite being in Kling... *ahem* portuguese; I don't even remember what I said and tested on it, but I recall I didn't open it (it was still in warranty).

I look forward for your review and tests. It still ticks valiantly on my bench despite some mishaps in medium voltage.

I plan to work on small segments to allow people enough time to provide feedback.  I ran into a couple of snags right from the start.   When you select the ACV function, then select frequency, how do you get it back to the standard mode?  The only way I saw was to change the function and return back to ACV.   

The other problem I see is I can't get the frequency counter to work.  Like the UNI-T meter, I wonder if they over spec'ed it.   Does yours work?

***
corrected

[rsjsouza]

Thanks for linking my video, despite being in Kling... *ahem* portuguese; I don't even remember what I said and tested on it, but I recall I didn't open it (it was still in warranty).

I look forward for your review and tests. It still ticks valiantly on my bench despite some mishaps in medium voltage.

I plan to work on small segments to allow people to provide feedback.  I ran into a couple of snags right from the start.   When you select the ACV function, then select frequency, how do you get it back to the standard mode?  The only way I saw was to change the function and return back to ACV.

   

One of the most confusing aspects of the U1282A is its button interface. When you go to the Frequency, you can long press the "Dual" button and get back to AC. However, if you go to either period or duty cycle by pressing the same "Hz" button, you can't go back to V unless you press the "Hz" button to get to the frequency and then long press the "Dual". I end up flipping the rotary switch.

The other problem I see is I can get the frequency counter to work.  Like the UNI-T meter, I wonder if they over spec'ed it.   Does yours work?

You can or can't? The frequency works alright, but there is a derating curve of sorts that is more aggressive on the V_AC Hz function when compared to the MHz range. I recall I can get several hundreds of kHz out of it. The MHz range goes to many MHz IIRC (it is specified to 10MHz)

I did a long feature overview of the U1282A and occasionally compared it to its sibling U1273A, which might be useful when you are exploring your meter. For convenience, it is copied below. 

I own a U1273A and a U1282A and had owned a U1233A. I haven't used the U1233A enough to have a strong opinion other than its size and packed features are a very nice feature. I tend to prefer the U1273A but the U1282A has its uses.

Leeching off bitseeker's excellent response, I have the following addenduns:
(I may be forgetting a few things)

U1273A:
- OLED display. The most controversial factor of this meter. Unbeatable indoors legibility and, if used in dark conditions, you will never be caught with a dark display (due to backlight timeout) while trying to evaluate the best places to put the probes. Its durability is unknown and various reports around this forum are concentrated on the previous model U1253 (only one or two concerned this model). Mine still works after 4~5 years of manufacturing (about 1-1/2 years of moderate use of about 1 hour per day). Threads here, here, here and here (there may be others).
- Decent speed autorange.
- Frequency measurements do not require the signal to have zero crossing - good for signals with  DC offset. (common to U127x/U128x)
- Various hold mechanisms (common to U127x/U128x), including a trigger (like an oscilloscope) and Auto hold.
- Built-in data logging with different trigger modes - the one I use the most is the event trigger, which allows to log only when a stable input is detected. (common to U127x/U128x)
- Low impedance ACV/DCV mode for eliminating ghost voltages (LoZ). Since in the bench I use several boards and power supplies and host PCs interconnected, this mode is quite useful to detect wide ground variations in unknown conditions. Lowest voltage difference is 3V_AC - here
- Can compensate for DC offset voltages when measuring resistance (smart ohms). I personally have seen myself using this mode more than I initially believed during my repairs around the house on HVAC, heater and other permanent installations.
- Good capacitance meter with excellent range: up to 33mF. Slow on auto-range, especially on higher ranges (somewhat expected).
- 3V Diode checker that tests in both directions so you don't have to swap the leads.
- Beep can only be fully disabled or fully enabled. No sensible settings to disable the turn on beep.
- Continuity tester has a very interesting melody setting. A gimmick.
- Uses AAA batteries (common to U127x/U128x). Not a big fan due to the fear of leakage, but this meter sees quite a bit of action and the batteries usually are replaced every 6~8 months with my use.
- Very well built and a bit tall for my taste, but it has good rotary switch and terminal jacks. The various buttons with the number of aggregated functions not always make much sense - I sometimes see myself pressing a number of buttons until I get what I want or just need to go back to the previous display.
- I love its leads (Dave dislikes them due to length) as they have banana jacks on both sides. Easy to plug accessories.
- Earlier versions, like mine, were sensitive to high-frequency RF on the input jacks that could alter the displayed value.

U1282A:
- LCD Display. Excellent size and quite clear.
- Its biggest drawback to me is the slow autorange.
- Frequency measurements do not require the signal to have zero crossing - good for signals with  DC offset. (common to U127x/U128x)
- Various hold mechanisms (common to U127x/U128x), including a trigger (like an oscilloscope) and Auto hold. However, on this meter the switch between the different auto-hold modes only via a setup menu - the U127x cycles as you press the button. To me this detracts from the functionality.
- Built-in data logging with different trigger modes - the one I use the most is the event trigger, which allows to log only when a stable input is detected. (common to U127x/U128x). Other modes are manual and timed - quite useful as well.
- It has NCV with configurable sensitivity settings. Despite this, I find this NCV still too sensitive for reasonable use. I prefer to use my Fluke LVD2 that is a spot tester.
- Good capacitance meter with excellent range: up to 100mF. Slow on auto-range, especially on higher ranges (somewhat expected).
- It has square wave output with configurable duty cycle and frequency. Since the frequency is only switchable on the setup menu, it is somewhat cumbersome to use for my taste.
- It has an input for remote control to perform manual hold of measurements. Perhaps it has its uses for others, but I haven't seen the need to purchase its accessory.
- 3V Diode checker. Lacks the auto-diode feature of the U127x that I like.
- Beep can be disabled more sensibly than U127x - either disable the turn on beep (leaving continuity beep still on) or disable everything. 
- Uses AAA batteries (common to U127x/U128x). Not a big fan due to the fear of leakage, especially because one of its big advertisements is the very long battery endurance. Better check them constantly.
- Very well built and large meter that can easily act as a weapon. It has rubbery feel rotary switch (if that is an issue or not it is a highly personal matter). The various buttons with the number of aggregated functions not always make much sense - I sometimes see myself pressing a number of buttons until I get what I want or just need to go back to the previous display. IP67 rated, but mine only sees action on the lab.
- Decent leads but do not allow plugging accessories.
- Came with USB accessory for firmware updating and data logging. A big plus to me.
- Did not come with the temperature probe. A fail in my opinion.
- Not plagued by high-frequency RF problem of the early U127x modes.

Interesting clips about autorange comparison and the melody setting (shameless plug)
Melody continuity:


Autorange comparison:

[joeqsmith]

One of the most confusing aspects of the U1282A is its button interface. When you go to the Frequency, you can long press the "Dual" button and get back to AC. However, if you go to either period or duty cycle by pressing the same "Hz" button, you can't go back to V unless you press the "Hz" button to get to the frequency and then long press the "Dual". I end up flipping the rotary switch.

    Thank you very much.  The UI has a college student's final project vibe to it.  Not what I would expect from Keysight.

FYI, mine came without documentation.  While the contents paper states it comes with it, there is a paper that talks about them going green.  No problem.   I go to get the manuals and the first thing they want was my email address.  Google search found the direct links.   I'm fine with electronic copies but don't make me have to create an account to gain access to them.   

You can or can't? The frequency works alright, but there is a derating curve of sorts that is more aggressive on the V_AC Hz function when compared to the MHz range. I recall I can get several hundreds of kHz out of it. The MHz range goes to many MHz IIRC (it is specified to 10MHz)

Unless I am not understanding the document you linked, they claim 100MHz. 

***
From your post:

- Frequency measurements do not require the signal to have zero crossing - good for signals with  DC offset. (common to U127x/U128x)

The meter I have appears to require the zero crossing.   You can't use it to look at digital signals for example.   

[joeqsmith]

In this intro video, I go through a basic checkout which includes looking at the frequency function.   

[HKJ]

What is the 100 division factor? Is it a special setting or an external probe (Sorry I do not have time to check the manual now).
A fast check on my U1282A showed that it worked at 1MHz with 4Vpp, but not at 2MHz.

[joeqsmith]

What is the 100 division factor? Is it a special setting or an external probe (Sorry I do not have time to check the manual now).
A fast check on my U1282A showed that it worked at 1MHz with 4Vpp, but not at 2MHz.

You need to press the Range selection to get it to work above 2MHz.     

[HKJ]

You need to press the Range selection to get it to work above 2MHz.   

That got me to 36MHz at 37MHz the readings where wrong (38.xxxMz).

The specifications saying <1MHz and <20Mhz for stated precision is obvious correct, but they do not say that the meter fails completely before maximum range value.

It is not that I will hold it against the meter, I will generally rate anything in the MHz range as outside a standard multimeter capabilities. A scope or a frequency counter with BNC connector (or better) and 50ohm input impedance is the tool for that.

[joeqsmith]

Not even half the rated frequency, which is what I am finding as well.   As I continued to increase the frequency, the meter will display more than 2X the actual.   Everything I tried ended with the same results.

The last meter I looked at was a UNI-T which advertised their counter over 200MHz.  I wouldn't expect Keysight to be on par with the UNI-T brand but here we are.     

HP > Agilent > Keysight > UNI-sigh 

[AVGresponding]

Not even half the rated frequency, which is what I am finding as well.   As I continued to increase the frequency, the meter will display more than 2X the actual.   Everything I tried ended with the same results.

The last meter I looked at was a UNI-T which advertised their counter over 200MHz.  I wouldn't expect Keysight to be on par with the UNI-T brand but here we are.     

HP > Agilent > Keysight > UNI-sigh

Hence my use of the derogatory "Keyshite". I am, sad to say, not surprised in the least.