Author Topic: 6.5 digit datalogging multimeter, opinions?  (Read 21383 times)

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Offline nukie

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #25 on: September 13, 2013, 11:14:36 pm »
So you just want a multimeter with lots of digits that can spew lots of data in a short time? I suggest comparing accuracy specs of the units especially 90 days and 1 year, not just digits vs cost.

There is no point to have a mountain of data when your multimeter is drifting your results will need to be calibrated to the performance of your multimeter. Finally, also consider the cost of calibration as the running cost.
 

alm

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #26 on: September 14, 2013, 09:00:50 am »
Is this about absolute accuracy or about accuracy relative to some reference point? In that case calibration (except zero calibration) is pretty much irrelevant. Sometimes just having a high resolution is enough.

If the project only takes a few months, then ongoing calibration is pretty much irrelevant as long as the 90 day stability is sufficient. I don't think you'll find huge differences in accuracy specs between the meters mentioned in this thread.
 

Offline EEVblog

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #27 on: September 15, 2013, 05:26:20 am »
Just to round out the group, GW/Instek have a 6.5 digit meter too, but about same price as the new lower end Agilent
http://www.metrictest.com/product_info.jsp?mfgmdl=INSTEK%20GDM-8261(N)
 

alm

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #28 on: September 15, 2013, 06:25:20 am »
I don't see the point of buying off-brand equipment like GW-Instek or Rigol (I don't consider them a decent brand for bench DMMs) unless they are substantially cheaper than Agilent or Fluke equipment. I wouldn't consider the Keithley 2100 either: no point paying for the Keithley name unless you're going to get a Keithley design. The Keithley 2000 (or any of the other Keithley 20xx models) is an excellent competitor to the Agilent 34401A (very similar in most regards) and a fine choice, although usually fairly expensive.

To me, the established brands are Agilent, Fluke and Keithley. Some of the older brands like Datron and Solartron have been bought or have pulled out of this market. Any other brand would have to provide substantial advantages for me to consider that, and even then I would first do extensive testing before putting it in production. In the past we've seen QC/build quality issues with the Rigol DM3061(?) and firmware issues in the Keithley/Array/Picotest meter. Apparently designing a decent bench DMM is non-trivial.
 

Offline bronson

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #29 on: September 15, 2013, 08:11:58 pm »
I picked up an HP 3457A and a Fluke 8840A (why does every part number end in "A"? it's like car models ending in "i") at the De Anza swap meet yesterday.  They have good displays and the output looks plausible...  Feeling lucky so far.

I'll need to spend some time making sure they aren't lying or drifting too bad.  I'm not quite sure how I'm going to do that when the best reference I have in my cabinet is probably an LM3940...  I'll figure out something better than just running each test with the meters in parallel hoping the 5 1/2 digit Fluke will keep the HP semi-honest.

alm's right, at this point I don't actually care too much about absolute accuracy or drift.  I want to get a bunch of readings with different amounts of weight on the cells and different excitation voltages across the bridge and look at the deltas.  Each measurement will only be a few seconds or minutes apart.  That said, this stuff is seriously fascinating...  I could very well be on the edge of a debilitating metrology habit.

Thanks to Dave and gazelle for naming models I didn't find.  Turns out there's a lot out there.  Who's up for a 6 1/2 digit shootout?
 

Offline robrenz

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #30 on: September 15, 2013, 08:22:08 pm »
this stuff is seriously fascinating...  I could very well be on the edge of a debilitating metrology habit.

Thanks to Dave and gazelle for naming models I didn't find.  Turns out there's a lot out there.  Who's up for a 6 1/2 digit shootout?

Beware!!! it is a very slippery slope :scared:

If you start looking again make sure you consider the Fluke 8846A. I purposely bit my tongue until now ;D

Offline bronson

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #31 on: September 15, 2013, 10:23:17 pm »
Oh, the 8846A was high on my original list.  Very high.  Love the dot matrix VFD: yes Virginia, you CAN have high contrast and trend graphs.  The only hit against it is the price.

And it's a pretty big hit.  :)
 

alm

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #32 on: September 15, 2013, 11:09:10 pm »
I picked up an HP 3457A and a Fluke 8840A (why does every part number end in "A"? it's like car models ending in "i") at the De Anza swap meet yesterday.
Good score, both are excellent meters in my opinion. HP sometimes releases B models, for example 3468A and 3468B. Just adding a A suffix by default is better then having 'the 3468B and the non-B 3468A, like the Fluke 87 and 87-III.

I'll need to spend some time making sure they aren't lying or drifting too bad.  I'm not quite sure how I'm going to do that when the best reference I have in my cabinet is probably an LM3940...  I'll figure out something better than just running each test with the meters in parallel hoping the 5 1/2 digit Fluke will keep the HP semi-honest.
If you're just looking for stability, then connecting both meters in parallel to the same source is a decent solution. If they track, then they are either drifting very similarly, or stable. Of course environmental factors (eg. temperature) might result in the former, but at least you can exclude defects.
 

Offline Attorney

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #33 on: October 06, 2013, 05:37:13 pm »
...I wouldn't consider the Keithley 2100 either: no point paying for the Keithley name unless you're going to get a Keithley design. The Keithley 2000 (or any of the other Keithley 20xx models) is an excellent competitor to the Agilent 34401A (very similar in most regards) and a fine choice, although usually fairly expensive.

Concerning the Keithley 2100, once Tektronix acquired/merged with Keithley, they finally had some leverage to address the firmware issues.  Any recently flashed 2100 should now be worthy of the the Keithley or Tek name.  I've owned the Keithley 2100 since June of last year and although I do not use its full complement of capabilities, I've detected no bizarre operating issues.  Everything, including USB connectivity and supplied software has worked as it should. 

The 2100 was manufactured by Array in Taiwan.   I also own the Array 3631A triple-output lab-grade supply -- made for Agilent as the E3631A.  The Array 3631A is the same supply, with a few more front panel features.  It was purchased last year at roughly half the cost of the same Agilent model.  Admittedly, I cannot go to Agilent for support if I need it, but I'll assume that risk.   I can do that as a hobbyist.  If I owned a business that depended on exceptional customer service, then I would pay the higher price for the Agilent-branded product.

Paul


 

Offline grenert

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #34 on: October 06, 2013, 06:25:02 pm »
The 2100 was manufactured by Array in Taiwan.   I also own the Array 3631A triple-output lab-grade supply -- made for Agilent as the E3631A.  The Array 3631A is the same supply, with a few more front panel features.  It was purchased last year at roughly half the cost of the same Agilent model.  Admittedly, I cannot go to Agilent for support if I need it, but I'll assume that risk.   I can do that as a hobbyist.  If I owned a business that depended on exceptional customer service, then I would pay the higher price for the Agilent-branded product.
I imagine Free e-, our resident HP/Agilent expert will chime in here, but I don't think there's a chance that Array makes the E3631A for Agilent.  The E3631A goes all the way back to HP days, now made in Malaysia in Agilent's plant.  I think the similarities end with the model number, selected to create confusion between the copy and the real thing.
 

alm

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #35 on: October 06, 2013, 09:47:02 pm »
Concerning the Keithley 2100, once Tektronix acquired/merged with Keithley, they finally had some leverage to address the firmware issues.  Any recently flashed 2100 should now be worthy of the the Keithley or Tek name.  I've owned the Keithley 2100 since June of last year and although I do not use its full complement of capabilities, I've detected no bizarre operating issues.  Everything, including USB connectivity and supplied software has worked as it should. 
Interesting, so they finally fixed it after it was on the market for a number of years. Did these fixes also make it to meters sold under brands like Array or Picotest? Too bad they did it after it gave Keithley a bad name. Reviews of the Keithley 2110 haven't been that impressive either (I would never buy it with that cheap crappy LCD), so I'm still not optimistic about future Keithley DMMs.

I also own the Array 3631A triple-output lab-grade supply -- made for Agilent as the E3631A.
I would agree with grenert that this sounds unlikely. My guess would be that they deliberately used the same model as Agilent (Owon did the same in their upcoming series of scopes by using a Tektronix model number) and copied the front panel layout.
 

Offline Fsck

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #36 on: October 06, 2013, 09:56:22 pm »
I also own the Array 3631A triple-output lab-grade supply -- made for Agilent as the E3631A.
I would agree with grenert that this sounds unlikely. My guess would be that they deliberately used the same model as Agilent (Owon did the same in their upcoming series of scopes by using a Tektronix model number) and copied the front panel layout.

should be fairly easy to figure out, just post pics of the interior!
"This is a one line proof...if we start sufficiently far to the left."
 

Offline Napalm2002

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6.5 digit datalogging multimeter, opinions?
« Reply #37 on: October 08, 2013, 05:17:52 pm »
Fluke 289. How does that convert bec it claims to be a 10,000 count meter. Doesn't give digits.
 

Offline ve7xen

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #38 on: October 08, 2013, 05:57:24 pm »
Fluke 289. How does that convert bec it claims to be a 10,000 count meter. Doesn't give digits.
10,000 counts = 4.5 digits (being generous with the .5 ...). Basically the digit count is the number of digits 0-9, and then add .5 if it has a leading digit with limited range. A 6.5 digit meter will be 1,000,000 count - 9,999,999 count.
73 de VE7XEN
 

alm

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #39 on: October 08, 2013, 05:58:14 pm »
 

Offline WarSim

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6.5 digit datalogging multimeter, opinions?
« Reply #40 on: October 08, 2013, 07:17:34 pm »


Thanks, I was looking for a video like this for the "special" people at work that insist that cal means adjusted and or repaired. 
 

Offline saturation

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #41 on: October 09, 2013, 12:36:12 pm »
Can anyone confirm this definitively?  Array was described as the ODM for some Keithley DMMs in the past, and seeing some of their work [ the 3710a eloads for example] shows they design well.  These seems very look alike and the Array is 50% cheaper.

https://www.eevblog.com/forum/chat/instek-3000-series/msg82910/#msg82910

Array vs Agilent/HP! :-//



The 2100 was manufactured by Array in Taiwan.   I also own the Array 3631A triple-output lab-grade supply -- made for Agilent as the E3631A.  The Array 3631A is the same supply, with a few more front panel features.  It was purchased last year at roughly half the cost of the same Agilent model.  Admittedly, I cannot go to Agilent for support if I need it, but I'll assume that risk.   I can do that as a hobbyist.  If I owned a business that depended on exceptional customer service, then I would pay the higher price for the Agilent-branded product.
I imagine Free e-, our resident HP/Agilent expert will chime in here, but I don't think there's a chance that Array makes the E3631A for Agilent.  The E3631A goes all the way back to HP days, now made in Malaysia in Agilent's plant.  I think the similarities end with the model number, selected to create confusion between the copy and the real thing.
« Last Edit: October 09, 2013, 12:39:12 pm by saturation »
Best Wishes,

 Saturation
 

Offline free_electron

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #42 on: October 15, 2013, 08:28:58 pm »
BULLSHIT.

The e3631 is much older than array, and is a true HP design.
if anything that array thing is a cheap knock-off.
« Last Edit: October 15, 2013, 08:32:19 pm by free_electron »
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Any comments, or points of view expressed, are my own and not endorsed , induced or compensated by my employer(s).
 

Offline saturation

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #43 on: October 16, 2013, 02:52:46 pm »
Thanks freee- for that enthusiastic reply.  From eevblog archives:

https://www.eevblog.com/forum/reviews/teardown-agilent-e3631a-power-supply-%28picture-heavy%29/45/



BULLSHIT.

The e3631 is much older than array, and is a true HP design.
if anything that array thing is a cheap knock-off.
Best Wishes,

 Saturation
 

Offline madshaman

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6.5 digit datalogging multimeter, opinions?
« Reply #44 on: October 16, 2013, 03:21:09 pm »
+1 on the 3457A, mine's never had a problem.

Some day I will find a Keithley 2002 in a dumpster :P
To be responsible, but never to let fear stop the imagination.
 

Offline Attorney

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #45 on: October 30, 2013, 01:31:21 pm »
BULLSHIT.

The e3631 is much older than array, and is a true HP design.
if anything that array thing is a cheap knock-off.

Knock-off or otherwise -- Place the Array 3631A side-by-side with the HP/Agilent E3631A.  Tear it down and look inside.   Examining the two, you can detect subtle differences but the component quality is identical.  If anything, the nod may go to the Array for its USB interface (if its important to you) and use of some newer semiconductor types since the design of the E3631.  The Array has the exact look, feel, and mass of the E3631A right down to the screw heads.  I see no firmware bugs with the Array, but then I've not used much of its programming capabilities.

Bashing a product is fine, but at least get to know the product before depending on the maligning that goes on when reading the blogs.  This would be a good upcoming product comparison for for Dave Jones. 

Paul
 

alm

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #46 on: October 30, 2013, 01:40:45 pm »
I don't see any bashing of the instrument going on. If the HP/Agilent E3631 pre-dates Array and is manufactured in a different country, then the Array design can only be a knock-off. The quality of this clone may vary from crappy to decent, but it's still a copy. Just like the Hakko soldering station knock-offs of varying quality that are available.

It may or may not perform better than the other Chinese low to mid-end power supply manufacturers like Rigol or Atten, but don't kid yourself thinking you bought an Agilent product.
 

Offline Attorney

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #47 on: October 30, 2013, 02:27:57 pm »
I don't see any bashing of the instrument going on. If the HP/Agilent E3631 pre-dates Array and is manufactured in a different country, then the Array design can only be a knock-off. The quality of this clone may vary from crappy to decent, but it's still a copy. Just like the Hakko soldering station knock-offs of varying quality that are available.

It may or may not perform better than the other Chinese low to mid-end power supply manufacturers like Rigol or Atten, but don't kid yourself thinking you bought an Agilent product.

Right.  I don't think there's any self-kidding going on.  The Array PS is not an Agilent product.  As noted earlier, I said that as a hobbyist, I can live with support that is not up to Agilent's gold standard.  If my livelihood depended on the supply, I would look to the Agilent. 

That out of the way, the underlying issue is whether or not the Array is: (1) anywhere equal to the E3631A in terms of product quality; and (2) is Array involved in any way with the manufacture of recent E3631A supplies?   I was told by a manufacturer's rep that Array was building newer E3631As.   In my line of business, I live or die by the evidence.  Based on my limited research, I do not know as a conclusive fact whether all, or some portion of the newer E3631As are manufactured by Array in Taiwan -- and not Agilent in Malaysia.   I am certain we can find an Agilent rep who would refute any claim that recent  E3631As are manufactured with outside assistance.

Again, put the two supplies side-by-side and compare everything from electronic components, circuit trace layout, machine screws, wiring and grounding practices as well as fit and finish.   Array is not Agilent and vice-versa.  For sure, Array is leveraging a portion of the model number to their advantage -- and this appears to be upsetting many people.   If Agilent has an issue with it, then it would bother me.  OTOH, if Agilent has no issue and they use Array in some form, then none of us should take issue with it.  Unfortunately, seeking the truth would require getting inside the two organizations.

Paul
 

alm

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #48 on: October 30, 2013, 03:17:50 pm »
I think it's obvious that the Agilent E3631A is an Agilent design. I haven't seen any evidence of Agilent outsourcing manufacturing of their own designs. They have sometimes rebadged instruments designed and manufactured by others (the Rigol DSOs come to mind), but not their own designs as far as I know. And even if they did, selling them under the Array name is unlikely to be authorized by Agilent. Why would Agilent license Array to sell these instruments under their own name?

Assuming they are not an ODM for Agilent, I consider copying the design and model number is an attempt to trick the customer into buying an Array product thinking it's identical to the Agilent product. I don't like to be deceived; whether Agilent thinks this is worth spending legal fees on is irrelevant to that feeling.
 

Offline Attorney

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Re: 6.5 digit datalogging multimeter, opinions?
« Reply #49 on: October 30, 2013, 05:23:56 pm »
Why would Agilent license Array to sell these instruments under their own name?

It's a good question and a similar situation that Array faced with Keithley (pre-Tektronix).  Recall that the Keithley 2100 DMM is clearly an Array-manufactured product.  Yet, the same DMM is still sold under the Keithley and Array names, although Array may have a global geography limitation that's acceptable to Keithley.   Also, keep in mind that Keithley is still distributing the 2100 so the relationship between Keithley/Tektronix and Array must not have soured any. 

BTW, at the risk of sounding like an Array cheerleader, the 2100 is one of the most maligned electronics devices I've seen.  Granted, in 2007/2008 the maligning was probably warranted.  Just like many DSO issues, most folks were quite happy with Array's hardware - but not the buggy firmware.  Eight firmware updates later ( in five years) and under the leadership of Tektronix, I think the 2100 is now worthy of the Keithley name. 

Quote
Assuming they are not an ODM for Agilent, I consider copying the design and model number is an attempt to trick the customer into buying an Array product thinking it's identical to the Agilent product. I don't like to be deceived; whether Agilent thinks this is worth spending legal fees on is irrelevant to that feeling.

At the price level of the Array and Agilent 3631A models, I think most folks are sophisticated buyers who should take the time to conduct their due-diligence to at least ask the question.  Of course, that demands a forthright and truthful answer from the manufacturers.

Paul

   

 


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