Test Equipment Anonymous (TEA) group therapy thread

[ch_scr]

I did notice that it had multiple channels (rear ports) but I imagine these values can only be read over USB/GPIB.  I am looking for multichannel instruments so these ticked all the boxes.  I might also be buying these to satisfy my curiosity in this subject.

At the moment I have no GPIB cables or accessories, and the time investment and money required to prepare all that is a whole other can of worms (I am starting brand new).  Even low baud rate RS232 is sufficient for my needs.  Both USB and RS232 are cheap and fast enough for my use case.  I have some old commodity hardware that I need to make use of, some old servers from the 2000s for data processing and logging.

There is the ADCMT 7352 dual 5 1/2 digit DMM, two independent channels in one box. There's one on ebay for reasonable money from Japan atm. With regard to "hobby grade GPIB2USB" there's the excellent Xyphro UsbGPIB. When re-using old machines, it'll work since they don't have much to do (except e.g. running Linux and a Python script), but running potentially long stretches at a time, these 20Y old machines might not be such a good idea - with their high idle power draw (100W+ if you're unlucky). Better get a NUC (already overkill), smth. based on older Intel Atom is really all that's needed (e.g. DELL WYSE 3040, which will be happy with ~ 5W).

[atokhy]

Hello atokhy,

[...]
For my requirements, I'll need to simultaneously measure every battery in a DUT and record the performance of the circuit that ends up charging and discharging it (a BMS).  I wonder if such a thing as a multi-multi-meter exists (so, a lower precision multimeter that does multiple simultaneous measurements at a lower rate).

Check out the 34970A with suitable multiplexer modules.
Take care when buying : there's an option that cancels/removes the 6 1/2-digit (22-bit) internal DMM.
And of course, you want to keep such a nice feature.
By using an unique 34901A multiplexer module, you can already monitor a 20S battery.

Device is easy to find on the second hand market : ebay (fleebay^^), T&M brookers,...

Thank you, this is exactly what I was looking for!  I was looking at Keithley data acquisition systems but I initially thought these were "master" units that hooked to other measuring devices over GPIB.  I didn't know about this whole "option" system, so I did not understand what they were at first.  Now I know (my newbie is showing)!

There is also the 34972A model which has USB/LAN and webserver access, but they appear to be a lot more expensive ($200 vs $800 used).  After watching a few videos on their use, specifically this video it looks like there are other people out there doing this!

I did notice that it had multiple channels (rear ports) but I imagine these values can only be read over USB/GPIB.  I am looking for multichannel instruments so these ticked all the boxes.  I might also be buying these to satisfy my curiosity in this subject.

At the moment I have no GPIB cables or accessories, and the time investment and money required to prepare all that is a whole other can of worms (I am starting brand new).  Even low baud rate RS232 is sufficient for my needs.  Both USB and RS232 are cheap and fast enough for my use case.  I have some old commodity hardware that I need to make use of, some old servers from the 2000s for data processing and logging.

There is the ADCMT 7352 dual 5 1/2 digit DMM, two independent channels in one box. There's one on ebay for reasonable money from Japan atm. With regard to "hobby grade GPIB2USB" there's the excellent Xyphro UsbGPIB. When re-using old machines, it'll work since they don't have much to do (except e.g. running Linux and a Python script), but running potentially long stretches at a time, these 20Y old machines might not be such a good idea - with their high idle power draw (100W+ if you're unlucky). Better get a NUC (already overkill), smth. based on older Intel Atom is really all that's needed (e.g. DELL WYSE 3040, which will be happy with ~ 5W).

At the moment there are ADCMT 7461A's and ADCMT 7351A's going for auction on Ebay from a US seller and the auction isn't as crowded so I should get better deals here.  These must be from a Japanese manufacturer in the US getting rid of their old test equipment (Toyota maybe). The idle power consumption on the 7461A is pretty low according to my kill-a-watt (about 13W).  This might be the case with the older Advantest R6581E-DC 7 1/2 digit models which I am hesitating on which could act as a calibration source.  The 8 1/2 digit advantest is beyond my budget though if I settle for 7 1/2 as my highest precision multimeter.  Idle power consumption may not be as much of a big deal for me as I have already installed a 9kW solar power system for this house so I should be able to power quite a few toys  .

[timeandfrequency]

There is also the 34972A model which has USB/LAN and webserver access, but they appear to be a lot more expensive ($200 vs $800 used).

Yes the 34972A features more modern interfaces and it's price reflects these improvements.
By using a quality RS232 to USB converter you'll be in business quickly, even with the older 34970A.
These TE are 'all in one' acquisition systems with comprehensive features and they fit to many different use cases. Even with one or two muliplexer modules, you have true versatility.

Free Keysight sotfware to control these acquisition units.

If you want to set up a whole test bench with multiple voltmeters, electronic loads and power supplies, consider using a multi serial PCI card or the old school GPIB bus.
As far as I remember, you can hook 31 devices to a GPIB bus. And many TE from renowed brands feature a GPIB interface. You might also see 'IEEE488' : this is just an alias name for GPIB.

You'll also need :
- USB to GPIB converter
- GPIB cable

[Cyclotron]

I've developed a problem even though I mostly lurked in the background. The affliction seems to pass around without engagement.
Oddly, with all this gear, I still turned it all on to ensure I didn't trip a breaker instead of calculating or measuring the load. Obviously, the PSUs can produce far more load if they are active.

I don't do this for a living, but I always wanted to. My skills in IT offer more return on hours spent, though.
I appreciate the community.

I noted my prior post here and did another image from a similar perspective but had to back it up to capture more of my latest affliction. I surprised myself. I didn't realize how sick I'd been.
The red arrows indicate new stuff in the "now" image vs. the "August" image. I failed to point out the entire new workbench on the left. 
You can't see the fumes extractor, a couple of Fluke and Agilent hand-helds, lots of hand tools, an entire healing rack to the right, and behind the camera view where projects and items for repair sit in various states waiting for examination or parts.
I've added GPS and Rb 10mhz reference clocks, and there are some other analog meters I am not picturing here.

I think someone needs to take ebay and other options away from me. Much of these items were broken when I bought them and I've repaired them and put them to work. I've actually had to donate a few items to my local high school robotics club to trim the ship.

Now I need a drink.

[TERRA Operative]

The 34972A is a nice bit of kit, worth buying over the 34970A if ypu will be working 'in the field' away from the bench.

The USB function allows you to make programs using the Agilent benchlogger software and load onto a USB stick to insert into the rear USB port to allow for stand-alone automated testing.

I built up a test rig recently for testing individual cell voltages on large 52-cell grid-tie batteries out in the field and it works fantastic, the client has me building another setup at the moment.

These instruments are fun things to play with.


On a side note, you can read out the number of relay actuations on the internal relays from the front panel, and the module relays from the front panel or from the PC software. That way you can replace any worn out relays for better test results on second-hand modules.
I found my results were much better and more consistent when I did this, some of the 2nd hand 20-channel modules I picked up had relays were up at 2 million actuations!
If you do a before and after ohms test with wire links to short each channel (so you are effectively testing the relay contacts) you'll see much better consistency across multiple runs when you swap out old relays, which is expected..

Also, the 34972A (and maybe the 34970A, not sure) has a CR2032 coin cell inside. A potential source of cheap units with an easy fix if it's throwing errors due to a flat battery.
Just read the service manual and be careful as there are some screws around the DMM module which if removed can apparently potentially affect the calibration. (But you'll need to remove them if you need to replace any of the three internal relays anyway).

Also, replacement VFD displays are available from the usual online marketplaces. Due to the nature of these instruments, they can be left on for long periods during logging, and the red phosphor in the display tends to dim quicker than the green, so a new VFD can be a nice upgrade if the budget allows.

[atokhy]

There's also a larger unit, the 34980A (USB/LAN) which is the full rack unit.  The used price for these is about the same as the 34972A (USB) and they come with 40 channel cards, which aren't priced any differently than the 34972A cards on ebay.  I might look into those as well, since unless I'm working on EV batteries, I don't think I'll need more than 40/80 channels (168VDC / 336VDC max respectively).

I see that as the upper limit for my application/use case.

[Cyclotron]

I've developed a problem even though I mostly lurked in the background. The affliction seems to pass around without engagement.
Oddly, with all this gear, I still turned it all on to ensure I didn't trip a breaker instead of calculating or measuring the load. Obviously, the PSUs can produce far more load if they are active.

I don't do this for a living, but I always wanted to. My skills in IT offer more return on hours spent, though.
I appreciate the community.

I noted my prior post here and did another image from a similar perspective but had to back it up to capture more of my latest affliction. I surprised myself. I didn't realize how sick I'd been.
The red arrows indicate new stuff in the "now" image vs. the "August" image. I failed to point out the entire new workbench on the left. 
You can't see the fumes extractor, a couple of Fluke and Agilent hand-helds, lots of hand tools, an entire healing rack to the right, and behind the camera view where projects and items for repair sit in various states waiting for examination or parts.
I've added GPS and Rb 10mhz reference clocks, and there are some other analog meters I am not picturing here.

I think someone needs to take ebay and other options away from me. Much of these items were broken when I bought them and I've repaired them and put them to work. I've actually had to donate a few items to my local high school robotics club to trim the ship.

Now I need a drink.

\


Add the updated photo I missed earlier.

[TERRA Operative]

You still have empty floor space and some clear horizontal surfaces.

Buy more gear!

[ch_scr]

I've developed a problem even though I mostly lurked in the background. The affliction seems to pass around without engagement.
Oddly, with all this gear, I still turned it all on to ensure I didn't trip a breaker instead of calculating or measuring the load. Obviously, the PSUs can produce far more load if they are active.

I don't do this for a living, but I always wanted to. My skills in IT offer more return on hours spent, though.
I appreciate the community.

I noted my prior post here and did another image from a similar perspective but had to back it up to capture more of my latest affliction. I surprised myself. I didn't realize how sick I'd been.
The red arrows indicate new stuff in the "now" image vs. the "August" image. I failed to point out the entire new workbench on the left. 
You can't see the fumes extractor, a couple of Fluke and Agilent hand-helds, lots of hand tools, an entire healing rack to the right, and behind the camera view where projects and items for repair sit in various states waiting for examination or parts.
I've added GPS and Rb 10mhz reference clocks, and there are some other analog meters I am not picturing here.

I think someone needs to take ebay and other options away from me. Much of these items were broken when I bought them and I've repaired them and put them to work. I've actually had to donate a few items to my local high school robotics club to trim the ship.

Now I need a drink.

\


Add the updated photo I missed earlier.

I spy some ESI device(s) (?) in the upper left corner... Any chance to get a picture of the beautys? Otherwise, yeah TEA tends to fill the available space 

[tggzzz]

Otherwise, yeah TEA tends to fill the available space 

That's the point at which your hobby becomes less expensive.

[Ice-Tea]

Eh, no, that's when you start renting more space.

[tggzzz]

Eh, no, that's when you start renting more space.

Shut up. Go away. Stop making suggestions like that.

Please

[Ice-Tea]

You're right. Renting is stupid. Which is why I'm in the process of buying an additional place.

[m k]

Don't forget foreign opportunities, they are not far and exporting can have local subsidies.

[Ice-Tea]

When you're bored: just let me know. Tons of stuff to sink your teeth in. Pick your poison: RF? Power Supplies? Scopes?

[m k]

Do you have an outlet section, or some other secondary of secondaries part of the store?

[McBryce]

I've developed a problem even though I mostly lurked in the background. The affliction seems to pass around without engagement.
Oddly, with all this gear, I still turned it all on to ensure I didn't trip a breaker instead of calculating or measuring the load. Obviously, the PSUs can produce far more load if they are active.

I don't do this for a living, but I always wanted to. My skills in IT offer more return on hours spent, though.
I appreciate the community.

I noted my prior post here and did another image from a similar perspective but had to back it up to capture more of my latest affliction. I surprised myself. I didn't realize how sick I'd been.
The red arrows indicate new stuff in the "now" image vs. the "August" image. I failed to point out the entire new workbench on the left. 
You can't see the fumes extractor, a couple of Fluke and Agilent hand-helds, lots of hand tools, an entire healing rack to the right, and behind the camera view where projects and items for repair sit in various states waiting for examination or parts.
I've added GPS and Rb 10mhz reference clocks, and there are some other analog meters I am not picturing here.

I think someone needs to take ebay and other options away from me. Much of these items were broken when I bought them and I've repaired them and put them to work. I've actually had to donate a few items to my local high school robotics club to trim the ship.

Now I need a drink.

\


Add the updated photo I missed earlier.

Thanks! Now I can stop looking for the non-existent red arrows in the first post. I was starting to get worried that I either needed glasses or I had started on the sauce a little too early today!

McBryce.

[Ice-Tea]

Do you have an outlet section, or some other secondary of secondaries part of the store?

No. Every once in a while I give up on finding the time for some piece and then I send it off to an eBay auction, starting price 1€ ;-)

[m k]

Just bought a busted TDS784D

How many thermistors these things have?

https://www.eevblog.com/forum/repair/tektronix-tds784a-acquisition-borard-test-fail/