Handheld meter robustness testing

[danno_cj]

For long time data logging is not recommended to use Bluetooth connection, use cable or store the values on measuring device and retrieve the log file later. The later way was selected by Owon on their BT meters. Since the dmm chip doesn't have memory to store the values, the Owon meters uses the BT module as storage device. This method have several advantages, lower power consumption especially when the take the reading at several seconds because between recording the values the BT module enter in sleeping mode with close to zero power consumption. Also the phone is only needed initially and when you recover the data. Brymen should implement this on their new BT meters. One problem may be the storage space available. The BT module used by Brymen have 256k, the BT module found inside on Owon meters have 512k. Of course not all memory is available for recording but for Owon still alow 10000 samples to be saved.

[joeqsmith]

For long time data logging is not recommended to use Bluetooth connection, use cable or store the values on measuring device and retrieve the log file later. The later way was selected by Owon on their BT meters. Since the dmm chip doesn't have memory to store the values, the Owon meters uses the BT module as storage device. This method have several advantages, lower power consumption especially when the take the reading at several seconds because between recording the values the BT module enter in sleeping mode with close to zero power consumption. Also the phone is only needed initially and when you recover the data. Brymen should implement this on their new BT meters. One problem may be the storage space available. The BT module used by Brymen have 256k, the BT module found inside on Owon meters have 512k. Of course not all memory is available for recording but for Owon still alow 10000 samples to be saved.

I looked at an Owon BT meter.  Like many of the low end meters I have evaluated, the electrical robustness was poor.   Mine actually came with glass unfilled fuses.   I never life cycled the selector switch on that meter as mechanically, it looked like other bottom end meters where they placed the vias dead center of the pads.  That switch would have never survived. 

But let's ignore all the problems with the meter and talk about the BLE interface.   Owon, unlike Brymen, did not release the protocol to the public domain.   This means I am left to reverse engineer it or if lucky maybe find an application that would still be supported.   With Brymen, I can just roll my own software (which I have) and there is no wasted time reverse engineering.  The real advantage of this isn't just to write some crap plotting program like I demonstrated, but to allow me to integrate the meter as part of a larger test.   Something I have frequency done. 

Wow, you can save a whole 10,000 samples.  At 5Hz, that's a little over a half hour.   With the Brymen BM78xBT, I'm running tests in the days, not minutes.  I like having the data live as I can monitor what is going on during my experiment, not after the fact. 

If you don't mind the poor mechanics and lack of electrical robustness, there is Dave's 121GW.  While you can store data locally to a SD card, you can not off load it over BLE.  So you have to pull the card and read it.  I cracked the card reader on one of mine.   I understand they had a lot of problems with the banana connectors splitting.  The protocol is open and I have written my own software to talk to it over BLE.   It also came with actual safety fuses. 

Really, I could care less what products people buy.  Buy the tools you need.  Don't be one of the idiots who writes me asking about how to modify their handheld meter and you will be fine.   Personally, I still like the BM869s of all the handhelds I have looked at. 

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From the page 1 index,
https://www.eevblog.com/forum/testgear/hear-kitty-kitty-kitty-nope-not-that-kind-of-cat/msg2053840/#msg2053840

[bdunham7]

I wonder if they just had not considered customers wanting to record for several days.  I have notified Brymen.

Given that most people are addicted to their phone, and don't have a spare just for data logging, I'd guess it wasn't intended for multi-day logging.

I'm one of those potential customers and I do have a separate phone (not just for logging--it is multipurpose) with a long battery life.  I use it with Fluke Connect, among other things.  I also do long term logging even on non-precision things like looking at how much power my freezer uses or how much my AC runs, but I don't use FC for this because the battery life is too short.  Extended bluetooth logging would be something I'd be interested in, although the battery life limits of the meter would still be an issue. 

[joeqsmith]

I'm one of those potential customers and I do have a separate phone (not just for logging--it is multipurpose) with a long battery life.  I use it with Fluke Connect, among other things.  I also do long term logging even on non-precision things like looking at how much power my freezer uses or how much my AC runs, but I don't use FC for this because the battery life is too short.  Extended bluetooth logging would be something I'd be interested in, although the battery life limits of the meter would still be an issue.

Sounds like a job for that Kill-a-Watt power meter rather than a handheld DMM. 

[bdunham7]

Sounds like a job for that Kill-a-Watt power meter rather than a handheld DMM.

I have a Kill-A-Watt and if energy consumption was all I wanted I'd use that--and I have.  But a DMM with a current clamp will tell me how often the device cycles on and for how long, peak starting currents, etc.  And a Kill-A-Watt won't work on a 5-ton AC condenser or my  pool pump.

[joeqsmith]

Sounds like a job for that Kill-a-Watt power meter rather than a handheld DMM.

I have a Kill-A-Watt and if energy consumption was all I wanted I'd use that--and I have.  But a DMM with a current clamp will tell me how often the device cycles on and for how long, peak starting currents, etc.  And a Kill-A-Watt won't work on a 5-ton AC condenser or my  pool pump.

I'm surprised you could get peak currents with a DMM in logging mode.  The peak modes normally latch from what I have seen so for long term logging, I am not sure how you reset it.

If you were just looking for something cheap, maybe something from this company:
https://microdaq.com/

Looks like a 5day battery life on this one, with 256k samples.  3Hz? 
https://microdaq.com/reed-instruments-current-voltage-data-logger.php

I have a good logger that would do what you want made by Hioki, but the price may be outside of the home hobby use. 

What are you using today? 

[Fungus]

I'm surprised you could get peak currents with a DMM in logging mode.

Maybe he processed the data log afterwards.

[bdunham7]

I'm surprised you could get peak currents with a DMM in logging mode.

What are you using today?

Fluke 289 with the i1010 or i400e current clamp.  "Peak" is a relative term, I mean milliseconds of motor starting current rather than microseconds of inrush.  The 289 does "event based recording" in addition to regular time intervals.  It will catch things like a failed motor start or even a hard start due to short cycle times. But even without that feature and just using time interval captures, just logging something like your AC, furnace or oven thermocycling is a perfectly reasonable use of a logging DMM that might go on for a considerable time.

[joeqsmith]

I use a HIOKI that can also record events as well and long term time intervals.   That seems more like what you are looking for than a simple DMM like this Brymen. 
Unless you define "considerable time" as 5 days,  I would not consider it.   The same for the peak detect.   I would make sure you read and understand the manuals (when they release them, which I have not seen BTW).

If you were looking for something cheap, maybe something like this one:
https://microdaq.com/dent-instruments-elitepro-xc.php

[danno_cj]

Joe I agree with you about the quality when you put side by side Owon versus Brymen but my post was about something else. Owon can also do unlimited data logging when the phone is connected to meter and can do something more: data logging without the phone. Why not Brymen add this feature?  If 10000  is enough or not to your specific job I can't say but usually when you monitoring many days you don't need to record every second the value, it can be taken several seconds parts and this 10000 samples can be enough. My post was actually a hidden request to Brymen with Joe as postman.

[joeqsmith]

Joe I agree with you about the quality when you put side by side Owon versus Brymen but my post was about something else. Owon can also do unlimited data logging when the phone is connected to meter and can do something more: data logging without the phone. Why not Brymen add this feature?  If 10000  is enough or not to your specific job I can't say but usually when you monitoring many days you don't need to record every second the value, it can be taken several seconds parts and this 10000 samples can be enough. My post was actually a hidden request to Brymen with Joe as postman.

Always best to just hit me upside the head with a brick (make any request/intention VERY clear).   

We know Byrmen dropped a feature to fit the BLE support into the firmware so I doubt we will see many changes to the meter's firmware.  My guess is they have higher priorities for now but I will ask them.   

[bdunham7]

That seems more like what you are looking for than a simple DMM like this Brymen.

I'm not looking to replace the advanced functions of the 289.  But I would like something I can connect up in the attic and then monitor for a few days on my phone.  Of course the AAA batteries are still a limitation even if they get the Bluetooth fully sorted.

[joeqsmith]

That seems more like what you are looking for than a simple DMM like this Brymen.

I'm not looking to replace the advanced functions of the 289.  But I would like something I can connect up in the attic and then monitor for a few days on my phone.  Of course the AAA batteries are still a limitation even if they get the Bluetooth fully sorted.

Unless you define " a few days " as 5,  I would not consider it.   Even if the phone had not disconnected, I think that's going to about the limit of it. 

[BILLPOD]

Check out this Owon clamp meter w/ bluetooth.   I got it specifically for the BLE.
https://www.amazon.com/OWON-Resistance-Capacitance-Measurement-Protection/dp/B0CTQDW33M/ref=asc_df_B0CTQDW33M?tag=bingshoppinga-20&linkCode=df0&hvadid=80676864348530&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=59456&hvtargid=pla-4584276327729431&msclkid=be3f6ce92c4b17e10ac504845b38e5c1&th=1

[bdunham7]

Unless you define " a few days " as 5,  I would not consider it.   Even if the phone had not disconnected, I think that's going to about the limit of it.

5 days would still be 10-15X as long as the IR3000FC lasts with its 2 AAA batteries.  That and I might consider getting a spare battery door and setting up a decent isolated power supply as a battery eliminator like Fluke has for their scopemeters and earlier DMMs like (867B and 8060A).  Or perhaps an add-on battery pack like the 4 C version for the 189--that logs for several weeks over the IR-USB cable and probably longer to internal memory.  Or maybe I just need to modify my IR3000FC to take an external supply or battery.  I guess I'll wait and see how the Brymen system finally turns out.

[joeqsmith]

Unless you define " a few days " as 5,  I would not consider it.   Even if the phone had not disconnected, I think that's going to about the limit of it.

5 days would still be 10-15X as long as the IR3000FC lasts with its 2 AAA batteries.  That and I might consider getting a spare battery door and setting up a decent isolated power supply as a battery eliminator like Fluke has for their scopemeters and earlier DMMs like (867B and 8060A).  Or perhaps an add-on battery pack like the 4 C version for the 189--that logs for several weeks over the IR-USB cable and probably longer to internal memory.  Or maybe I just need to modify my IR3000FC to take an external supply or battery.  I guess I'll wait and see how the Brymen system finally turns out.

"Peak" is a relative term, I mean milliseconds of motor starting current rather than microseconds of inrush.

That 5Hz sample rate enough (assuming Brymen is able to sort out the slow down) does not seem near fast enough and there is no event triggering like you mention.   You may be better off trying to get more run time out of your current setup.   

I don't think Dave ever stated if he proceeded with the order or not.  It's been a while since I have heard anything from Brymen.  Dave may have some insight about their scheduled release dates. 

[joeqsmith]

Brymen supplied me with an update today which they hope will address the 10X fault.   I have installed it and the test is underway.   

[BILLPOD]

I would think any meter with 'Auto-Hold' should work for getting a Peak reading.   Not regular 'hold', but 'Auto-Hold', which will log the peak, and over-ride it if there is a higher peak later.

[joeqsmith]

I can't imagine collecting the exact same peak reading for a few million samples would have any value for me.  For that, I wouldn't even log.  For work, I have had a need to look at mains over extended times but it's never come up at home.  If the $2000 unit wasn't up to the task, have a look at HIOKI's products:

https://www.hioki.com/us-en/products/pqa/power-quality/id_6735

[EEVblog]

I would think any meter with 'Auto-Hold' should work for getting a Peak reading.   Not regular 'hold', but 'Auto-Hold', which will log the peak, and over-ride it if there is a higher peak later.

"AutoHold" is designed to only take reading when the reading is stabilised, it's not for peaks, that's what the Crest function (Instantaneous Peak Hold) is for on Brymens for example. e.g. the BM2257 Crest mode can capture 5ms peaks.

[EEVblog]

I don't think Dave ever stated if he proceeded with the order or not.  It's been a while since I have heard anything from Brymen.  Dave may have some insight about their scheduled release dates.

I have ordered them. IIRC it might have been late July, but I'm not pushing them, it'll happen when it happens. Brymen are infamous for delaying releases.

[joeqsmith]

I have not heard anything about a Windows application yet.   

I wish there was a way to know if that 10X problem was solved outside of running them.  Nothing I have done seems to aggravate it.   It seems to just randomly show up.  My guess is it has something to do with the phone slowing down and running out of steam, causing some sort of pointer overrun. 

[joeqsmith]

Youtube recommended, actual arcflash caught on video.   

https://www.youtube.com/shorts/0s3rilsGSXM?feature=share

2nd person using a safety hook 

https://www.youtube.com/shorts/Hzs8YB1o5tc?feature=share

[KungFuJosh]

Hey Joe,

I think a lot of people would to see you blow this up: https://www.eevblog.com/forum/testgear/aneng-626-multimeter-hell/

Thanks,
Josh

[joeqsmith]

Maybe, but this is the one I want to play with.   I almost bought this meter rather than the Brymen BM869s.  The Brymen had a few features I wanted that this meter doesn't offer.  I also used HIOKI products and knew how robust they are and was interested in seeing what Brymen had to offer.