Test Equipment Anonymous (TEA) group therapy thread

[Specmaster]

Both the 3456A and 8505A have been on for approx 18 hours and I have some interesting results.

Test set-up. One of the AD584-M's powered by USB and powered continuously during the test. It was set to the indicated 9.99691V. That voltage is achieved at 25 C. I noticed during the Winter months that both my AD584-M's read lower due to ambient 21 C and take a while to warm up.

Results: Within approx 2 hours the 3456A stabilized and didn't vary all night. The 8505A did not fair well. It started out agreeing with the 3456A within one or two digits but as the test progressed it's measurement kept continuing to drift lower and lower and it wasn't until maybe 12 hours into the test that it stopped. The 3465A stabilized at 9.99693V to 95. The 8505A finally stopped drifting at 9.99676V to 78. In real world applications that doesn't mean a hill of beans. But to a volt-nut that's tragic. And if you compare it to the other three AD584-M voltages it begins to tell a story....


AD584-M         3456A            8505A

2.50066V          2.50061V       2.50062V

4.99794V          4.99792V       4.99790V

7.50011V          7.50012V       7.50000V

You can clearly see a pattern here. As the voltage increases the 8505A becomes more and more inaccurate.

And as further proof that something is amiss with the 8505A. Here is the other AD584-M
 
AD584-M         3456A             8505A

2.49937V          2.49938V       2.49938V 

5.00030V          5.00034V       5.00030V

7.50042V          7.50050V       7.50038V     

10.00096V       10.00108V      10.00094V

I don't have the ability to perform a full calibration on the 8505A and I don't think it's worth the effort and expense to send it to a cal lab. And unfortunately there are no cal labs within reasonable driving distance. But I suspect there's more going on here than just a calibration. The non-linear delta as the voltage increases is very suspicious. And in order to troubleshoot this DMM you need an extender board which is almost impossible to find. So my choices are sell this 8505A as a parts only unit or just quietly retire it and hope that one day an extender board shows up. I haven't decided what to do yet.

And as a side note. Speaking of the Siglent SDM 3055. I've decided that when the budget allows I'm going to sent it in for a full calibration rather than attempt to “tweak” it myself. And here it is measuring the same 9.99691V after it's been powered up for over 12 hours. I would expect at least a reading of 9.9968V or 69. And it's off at least that much on all the other references. 

Very interesting, and it's plain to see that you are not just teetering on the edge of that rabbit hole but rapidly sliding head first down it and for what other reason than OCD, I mean we are just talking of micro volts, when was the last time you had to measure or adjust something to that level  Bugs Bunny is waiting at the bottom of rabbit hole and when you get there, he'll ask you only the way he can "Err whats up Doc?"

[med6753]

Very interesting, and it's plain to see that you are not just teetering on the edge of that rabbit hole but rapidly sliding head first down it and for what other reason than OCD, I mean we are just talking of micro volts, when was the last time you had to measure or adjust something to that level  Bugs Bunny is waiting at the bottom of rabbit hole and when you get there, he'll ask you only the way he can "Err whats up Doc?"

If you go back and read what I wrote I stated in the real world this doesn't mean squat. Almost all the equipment we deal with could not care less about a few microvolts. The point here is if we have the tools to measure something it damn sure better be accurate. I had noticed that the 8505A was drifting over time but I couldn't tell if it was the reference or the DMM. I now have my answer. The 3456A clearly shows that once the reference is warmed up it's stable and the Fluke has the issue.

Same with the Siglent. It never agreed with the two Fluke 8800A's that track each other perfectly. The Siglent tracked consistently low. Yes, that bugged me from day one because it's inaccurate. (and now with the 3456A it further proves it is inaccurate) Tautech sent me the procedure for tweaking it and when I get a chance I'm going to give it a try. 

[Brumby]

But to a volt-nut that's tragic.

This is exactly why I'm stopping at 5.5 digits with my 3478A - which, with 4-wire measurement, is all I wanted.  (That has the potential to get me into a tizz as it is.)

[BU508A]

But to a volt-nut that's tragic.

This is exactly why I'm stopping at 5.5 digits with my 3478A - which, with 4-wire measurement, is all I wanted.  (That has the potential to get me into a tizz as it is.)

A 34401A has the same form factor but a much nicer display.
And more digits!

 

[BU508A]

For the folks in the US:

There is an Advantest ADCMT 7480t 8.5 Digit DC Multimeterin the bay:



https://www.ebay.com/itm/164693062060

Seller wants U$ 1800.- (or offer)

Imho this is a scam or something. So please be careful.
Seller has a rating of 88.9% @ 464 ratings.

Edit: Seller is located in Costa Rica.

[med6753]

I can't even render 5.5 and 6.5 digits and you want me to make the leap to 8.5 digits?

No. 

[factory]

Both the 3456A and 8505A have been on for approx 18 hours and I have some interesting results.

Test set-up. One of the AD584-M's powered by USB and powered continuously during the test. It was set to the indicated 9.99691V. That voltage is achieved at 25 C. I noticed during the Winter months that both my AD584-M's read lower due to ambient 21 C and take a while to warm up.

Results: Within approx 2 hours the 3456A stabilized and didn't vary all night. The 8505A did not fair well. It started out agreeing with the 3456A within one or two digits but as the test progressed it's measurement kept continuing to drift lower and lower and it wasn't until maybe 12 hours into the test that it stopped. The 3465A stabilized at 9.99693V to 95. The 8505A finally stopped drifting at 9.99676V to 78. In real world applications that doesn't mean a hill of beans. But to a volt-nut that's tragic. And if you compare it to the other three AD584-M voltages it begins to tell a story....


AD584-M         3456A            8505A

2.50066V          2.50061V       2.50062V

4.99794V          4.99792V       4.99790V

7.50011V          7.50012V       7.50000V

You can clearly see a pattern here. As the voltage increases the 8505A becomes more and more inaccurate.

And as further proof that something is amiss with the 8505A. Here is the other AD584-M
 
AD584-M         3456A             8505A

2.49937V          2.49938V       2.49938V 

5.00030V          5.00034V       5.00030V

7.50042V          7.50050V       7.50038V     

10.00096V       10.00108V      10.00094V

snip...

Unless I'm missing something the first reference is closer to the HP 3456A and the second reference is closer to the Fluke 8505A. Were the AD584-M references calibrated & can they be trusted?

David

[Hydron]

For the folks in the US:

There is an Advantest ADCMT 7480t 8.5 Digit DC Multimeterin the bay:

https://www.ebay.com/itm/164693062060

Seller wants U$ 1800.- (or offer)

Imho this is a scam or something. So please be careful.
Seller has a rating of 88.9% @ 464 ratings.

Looks like that is 1 negative rating out of 9 in the last year, and I gotta say it looks like a buyer problem on that one.
I'm not an ebay expert though mind (gotta say I miss 2000s trademe (NZ) - standard payment method was unrecoverable bank transfer, yet I don't think I got scammed once, though the selection wasn't great, especially TE wise).

[med6753]

Unless I'm missing something the first reference is closer to the HP 3456A and the second reference is closer to the Fluke 8505A. Were the AD584-M references calibrated & can they be trusted?

David

The AD584-M's are "calibrated" to the extent that they have labels indicating what their measured voltage was when they left the factory.

The 2nd AD584-M has always measured higher than it's stated labels and that's been verified with other DMM's. (And I also keep written records) So while it appears that the 8505A tracks closer that is not the case. 

[Zucca]

If I'd going to do something like Zucca is doing now, I'd ask my friend which is a very good tax advisor (Steuerberater).

I have incomes that will keep me floating during the retirement until I die.
My point is not to leave money or not get money from Germany that I can/could access in my paid german retirement plant. And I did not have a choice here, I had to pay for that.

Steuerberater was/is already on the list, not sure if it will help anyway. For sure I will give her a call.

It turns out I have to do nothing, there is an agreement beetween USA and Germany and all my money paid in the German system will be taken in account in the future when I will retire in USA (if God wants).

Interesting would have been if that agreement was not there, for example I would have moved to Mexico, then I could request to give my money back from the German system. Shit I would have preferred that.

I do not know why we are obligate to pay for our retirement, give me the freedom to do what I want with my money.... oh well.. back to work.

[Ice-Tea]

For the folks in the US:

There is an Advantest ADCMT 7480t 8.5 Digit DC Multimeterin the bay:

https://www.ebay.com/itm/164693062060

Seller wants U$ 1800.- (or offer)

Imho this is a scam or something. So please be careful.
Seller has a rating of 88.9% @ 464 ratings.

Looks like that is 1 negative rating out of 9 in the last year, and I gotta say it looks like a buyer problem on that one.
I'm not an ebay expert though mind (gotta say I miss 2000s trademe (NZ) - standard payment method was unrecoverable bank transfer, yet I don't think I got scammed once, though the selection wasn't great, especially TE wise).

Agree. Worst case, one out of 10 was not as described:

Contacted seller via Ebay, no response. Only half work as described.
Mettler Toledo XS104 Analytical Balances, Lot of 6, plus 4 more for spare parts. (#164260076249)
   
Buyer: e***m (209)
US $2,300.00 (Best offer was accepted)
   
Past month
Reply by vikiticingo. Left within past month.
Lot was sold for parts or not working, and described clearly as such.

[bd139]

F*ck.

Lenovo's supply chain apparently has broken down completely. 6 months lead time 
So, no new P15, however our "used stuff storage" still had a P53 in stock. They would have to special order the SSD and RAM upgrade and I would have to live with an RTX 3000. RAM and SSD should be no problem, and 64GB should be plenty for the forseeable future.

Told my boss that I would use my Tesla P100s for longer running calculations (i.e. if the RTX3k was not sufficient) and got the approval for the order.

But anyway. This should be a very decent notebook.

Same problem here. Stuck with the dell for months now 

Whats the problem here then, Covid or Brexit?

Quite a large number of problems unfortunately. Basically the entire semiconductor industry is leveraging TSMC capacity to produce 5nm and 7nm stuff as well as some other processes which aren't quite as new. Apple bought up nearly all the 5nm capacity which caused a supply problem with GPUs and CPUs when NVidia, AMD came in with their 5nm devices. Add to that the sudden demand of laptops and computing devices at home to cover the pandemic situation and some staffing problems due to the pandemic, plus panic buying of semiconductors by big users such as automobile manufacturers and it turned into a gigantic shit show of supply chain problems. Also if that's not bad enough, TSMC is being poked pretty hard by China at the moment on a political front after they started building 5nm factory nodes outside of the Chinese sphere of influence i.e. in America.

Ergo, everyone's waiting in a queue for TSMC, a company no one heard of until recently that pretty much has the ability to bring the entire planet to its knees. Even Intel production is up shit creek because half the support ICs that are dotted around the motherboards are fabbed by TSMC as well.

So Lenovo is stacked up with Intel CPUs but doesn't have enough stock or supply to produce any computers at the moment, right in the middle of the highest peak demand of computing in the last 20 years.

I'm sitting here looking at my nice 5nm ARM desktop, my nice 5nm ARM phone and laughing though because I got in super early

[Ero-Shan]

There's another PM2421 on the german 'bay: https://www.ebay.de/itm/Philips-Digital-Multimeter-PM-2421-altes-Gerat/133651733259

Less than 16 hours to go and standing at less than 16 €.

I'd like to have those claws! 

And, of course, I had forgotten about it this morning. It went for 25.50 €. Had I remembered, I'd bid at least 30 € for it. Sigh. Perfectly fits the "Items you forget to bid sell for a low price" rule.

[BU508A]

There's another PM2421 on the german 'bay: https://www.ebay.de/itm/Philips-Digital-Multimeter-PM-2421-altes-Gerat/133651733259

Less than 16 hours to go and standing at less than 16 €.

I'd like to have those claws! 

And, of course, I had forgotten about it this morning. It went for 25.50 €. Had I remembered, I'd bid at least 30 € for it. Sigh. Perfectly fits the "Items you forget to bid sell for a low price" rule.

Same here. Forgot to bid on some nice Bourns 3296W 20R trimpots. Missed it about on two minutes.
They are gone for ca. 20 Euro.     

https://www.ebay.de/itm/402666716862

[Robert763]

If I'd going to do something like Zucca is doing now, I'd ask my friend which is a very good tax advisor (Steuerberater).

I have incomes that will keep me floating during the retirement until I die.
My point is not to leave money or not get money from Germany that I can/could access in my paid german retirement plant. And I did not have a choice here, I had to pay for that.

Steuerberater was/is already on the list, not sure if it will help anyway. For sure I will give her a call.

It turns out I have to do nothing, there is an agreement beetween USA and Germany and all my money paid in the German system will be taken in account in the future when I will retire in USA (if God wants).

Interesting would have been if that agreement was not there, for example I would have moved to Mexico, then I could request to give my money back from the German system. Shit I would have preferred that.

I do not know why we are obligate to pay for our retirement, give me the freedom to do what I want with my money.... oh well.. back to work.

Because our society will take (some) care of us in any case and if not obligatory man would be too dumb to save  and some would take advantage.

[Zucca]

Because our society will take (some) care of us in any case and if not obligatory man would be too dumb to save  and some would take advantage.

I would have prefer the choice:"if you are too dumb, please sign here"

[Zucca]

And, of course, I had forgotten about it this morning. It went for 25.50 €. Had I remembered, I'd bid at least 30 € for it. Sigh. Perfectly fits the "Items you forget to bid sell for a low price" rule.

Same here. Forgot to bid on some nice Bourns 3296W 20R trimpots. Missed it about on two minutes.
They are gone for ca. 20 Euro.     

https://www.ebay.de/itm/402666716862

Gixen!

[mansaxel]

Soon time to put the fresh explosives to use..

[PA0PBZ]

There's another PM2421 on the german 'bay: https://www.ebay.de/itm/Philips-Digital-Multimeter-PM-2421-altes-Gerat/133651733259

Less than 16 hours to go and standing at less than 16 €.

I'd like to have those claws! 

And, of course, I had forgotten about it this morning. It went for 25.50 €. Had I remembered, I'd bid at least 30 € for it. Sigh. Perfectly fits the "Items you forget to bid sell for a low price" rule.

Same here. Forgot to bid on some nice Bourns 3296W 20R trimpots. Missed it about on two minutes.
They are gone for ca. 20 Euro.     

https://www.ebay.de/itm/402666716862

Don't cry guys, the buyer probably had a max bid of 50 Euro in there.

^{(Who am I kidding?)}

[Kosmic]

For the folks in the US:

There is an Advantest ADCMT 7480t 8.5 Digit DC Multimeterin the bay:



https://www.ebay.com/itm/164693062060

Seller wants U$ 1800.- (or offer)

Imho this is a scam or something. So please be careful.
Seller has a rating of 88.9% @ 464 ratings.

Edit: Seller is located in Costa Rica.

Yeah, I saw it this morning while reviewing my daily ebay's report 

I tried an offer at 1k and was refused automatically.

It's mostly a stripped down version of the 6581T. There's a thread about it over here with a lot of pictures: https://www.eevblog.com/forum/metrology/adcmt-7480t-8-5-digit-multimeter/

[mnementh]

Both the 3456A and 8505A have been on for approx 18 hours and I have some interesting results.

Test set-up. One of the AD584-M's powered by USB and powered continuously during the test. It was set to the indicated 9.99691V. That voltage is achieved at 25 C. I noticed during the Winter months that both my AD584-M's read lower due to ambient 21 C and take a while to warm up.

Results: Within approx 2 hours the 3456A stabilized and didn't vary all night. The 8505A did not fair well. It started out agreeing with the 3456A within one or two digits but as the test progressed it's measurement kept continuing to drift lower and lower and it wasn't until maybe 12 hours into the test that it stopped. The 3465A stabilized at 9.99693V to 95. The 8505A finally stopped drifting at 9.99676V to 78. In real world applications that doesn't mean a hill of beans. But to a volt-nut that's tragic. And if you compare it to the other three AD584-M voltages it begins to tell a story....


AD584-M         3456A            8505A

2.50066V          2.50061V       2.50062V

4.99794V          4.99792V       4.99790V

7.50011V          7.50012V       7.50000V

You can clearly see a pattern here. As the voltage increases the 8505A becomes more and more inaccurate.

And as further proof that something is amiss with the 8505A. Here is the other AD584-M
 
AD584-M         3456A             8505A

2.49937V          2.49938V       2.49938V 

5.00030V          5.00034V       5.00030V

7.50042V          7.50050V       7.50038V     

10.00096V       10.00108V      10.00094V

I don't have the ability to perform a full calibration on the 8505A and I don't think it's worth the effort and expense to send it to a cal lab. And unfortunately there are no cal labs within reasonable driving distance. But I suspect there's more going on here than just a calibration. The non-linear delta as the voltage increases is very suspicious. And in order to troubleshoot this DMM you need an extender board which is almost impossible to find. So my choices are sell this 8505A as a parts only unit or just quietly retire it and hope that one day an extender board shows up. I haven't decided what to do yet.

And as a side note. Speaking of the Siglent SDM 3055. I've decided that when the budget allows I'm going to sent it in for a full calibration rather than attempt to “tweak” it myself. And here it is measuring the same 9.99691V after it's been powered up for over 12 hours. I would expect at least a reading of 9.9968V or 69. And it's off at least that much on all the other references. 

Very interesting, and it's plain to see that you are not just teetering on the edge of that rabbit hole but rapidly sliding head first down it and for what other reason than OCD, I mean we are just talking of micro volts, when was the last time you had to measure or adjust something to that level  Bugs Bunny is waiting at the bottom of rabbit hole and when you get there, he'll ask you only the way he can "Err whats up Doc?"

It has nothing to do with volt-nuttery... He paid "New From the Distributor" price for that Siglent to have "one meter to rule them all". And now he has 3 high-end used meters that all agree (to certain definitions of the term) with each other... but NOT with that "brammy-spankin' new meter", and haven't since he got it.

I can see where that's a reasonable gripe. I'd have sent it back and requested they double-check it under warranty myself. Given that it's long past warranty period now, I agree with the argument that it should be re-cal'd by a Cal Lab & given a cal cert, so he has that "one cal'd meter to rule them all", which is what he paid the big bux for in the first place.

mnem
*huggles his 189 close*

[mnementh]

Because our society will take (some) care of us in any case and if not obligatory man would be too dumb to save  and some would take advantage.

I would have prefer the choice:"if you are too dumb, please sign here"

The point of Social Security was not to force people to save for their retirement; it was instituted with the notion that an employer had an obligation to his employees aside from just the hard-fought wages, but also to make a better world for the employee as well. The concept was always that the employer matched what the employee paid into the system, such that there was a cooperative effort towards real SOCIAL SECURITY.

Of course,  those same bastards who've been fuckerizing the minimum wage for my entire lifetime also couldn't be satisfied with just creating a wage slavery economy; they had to make sure that pittance they paid into SS was either subsidized by loss of other compensation or outright raping SS itself.

The motherfuckers who're telling you SS is bankrupt are liars; they are an always have been after one thing: a chance to steal that one last remaining reserve of solvent cash left in the Ponzi Scheme known as Supply-Side Economics.

If you've only ever worked as an "Independent Contractor" you wouldn't know this... that whole class of job disopportunity was created by those bastards as an end run around this institution. People don't realize when they take that "job" that they are legally taking on the fiscal responsibility of both the employee and the employer... and therefore it is their obligation as their own employer to match what the employee pays into the system.

mnem
 

[Kosmic]

Both the 3456A and 8505A have been on for approx 18 hours and I have some interesting results.

Test set-up. One of the AD584-M's powered by USB and powered continuously during the test. It was set to the indicated 9.99691V. That voltage is achieved at 25 C. I noticed during the Winter months that both my AD584-M's read lower due to ambient 21 C and take a while to warm up.

Results: Within approx 2 hours the 3456A stabilized and didn't vary all night. The 8505A did not fair well. It started out agreeing with the 3456A within one or two digits but as the test progressed it's measurement kept continuing to drift lower and lower and it wasn't until maybe 12 hours into the test that it stopped. The 3465A stabilized at 9.99693V to 95. The 8505A finally stopped drifting at 9.99676V to 78. In real world applications that doesn't mean a hill of beans. But to a volt-nut that's tragic. And if you compare it to the other three AD584-M voltages it begins to tell a story....


AD584-M         3456A            8505A

2.50066V          2.50061V       2.50062V

4.99794V          4.99792V       4.99790V

7.50011V          7.50012V       7.50000V

You can clearly see a pattern here. As the voltage increases the 8505A becomes more and more inaccurate.

And as further proof that something is amiss with the 8505A. Here is the other AD584-M
 
AD584-M         3456A             8505A

2.49937V          2.49938V       2.49938V 

5.00030V          5.00034V       5.00030V

7.50042V          7.50050V       7.50038V     

10.00096V       10.00108V      10.00094V

I don't have the ability to perform a full calibration on the 8505A and I don't think it's worth the effort and expense to send it to a cal lab. And unfortunately there are no cal labs within reasonable driving distance. But I suspect there's more going on here than just a calibration. The non-linear delta as the voltage increases is very suspicious. And in order to troubleshoot this DMM you need an extender board which is almost impossible to find. So my choices are sell this 8505A as a parts only unit or just quietly retire it and hope that one day an extender board shows up. I haven't decided what to do yet.

And as a side note. Speaking of the Siglent SDM 3055. I've decided that when the budget allows I'm going to sent it in for a full calibration rather than attempt to “tweak” it myself. And here it is measuring the same 9.99691V after it's been powered up for over 12 hours. I would expect at least a reading of 9.9968V or 69. And it's off at least that much on all the other references. 

Very interesting, and it's plain to see that you are not just teetering on the edge of that rabbit hole but rapidly sliding head first down it and for what other reason than OCD, I mean we are just talking of micro volts, when was the last time you had to measure or adjust something to that level  Bugs Bunny is waiting at the bottom of rabbit hole and when you get there, he'll ask you only the way he can "Err whats up Doc?"

It has nothing to do with volt-nuttery... He paid "New From the Distributor" price for that Siglent to have "one meter to rule them all". And now he has 3 high-end used meters that all agree (to certain definitions of the term) with each other... but NOT with that "brammy-spankin' new meter", and haven't since he got it.

I can see where that's a reasonable gripe. I'd have sent it back and requested they double-check it under warranty myself. Given that it's long past warranty period now, I agree with the argument that it should be re-cal'd by a Cal Lab & given a cal cert, so he has that "one cal'd meter to rule them all", which is what he paid the big bux for in the first place.

mnem
*huggles his 189 close*

What if the ref in the Siglent continue drifting after calibration ? Personally I would leave it on 24/7 (with screen off) to try to stabilize and age the voltage reference a little bit before sending it in for calibration. It's a shame it has not been done before building the meter. They could also use a better ref that doesn't really need aging.

[mnementh]

It has nothing to do with volt-nuttery... He paid "New From the Distributor" price for that Siglent to have "one meter to rule them all". And now he has 3 high-end used meters that all agree (to certain definitions of the term) with each other... but NOT with that "brammy-spankin' new meter", and haven't since he got it.

I can see where that's a reasonable gripe. I'd have sent it back and requested they double-check it under warranty myself. Given that it's long past warranty period now, I agree with the argument that it should be re-cal'd by a Cal Lab & given a cal cert, so he has that "one cal'd meter to rule them all", which is what he paid the big bux for in the first place.

mnem
*huggles his 189 close*

What if the ref in the Siglent continue drifting after calibration ? Personally I would leave it on 24/7 (with screen off) to try to stabilize and age the voltage reference a little bit before sending it in for calibration. It's a shame it has not been done before building the meter. They could also use a better ref that doesn't really need aging.

That's all just armchair quarterbacking at this point. My suspicion is that the difference is more likely a matter of how this older generation of meters was compensated for circuit loading vs how this new generation is compensated, and that it may very well still have that discrepancy, and that discrepancy may very well not be linear.

Bottom line is that it is entirely possible for all 4 meters to read differently at this level of resolution and still be considered correct... it has to do with the process, not the numbers on the screen.

That is the major brain-fuckery of volt-nuttery: Uncertainly principle multiplied by the inherent inaccuracy of observation=Plato's Cave.

mnem
"Man with one watch always knows what time it is. Man with two is never sure." ~allegedly Chinese proverb

[Mortymore]

...

Of course that meter has deviations! med6753 cuted the meter's ears off, and turned it into the Van Gogh of the meters.
It will never be the same again