Author Topic: EEVblog #170 - Agilent FAIL!  (Read 30490 times)

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Offline Kiriakos-GR

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Re: EEVblog #170 - Agilent FAIL!
« Reply #50 on: May 21, 2011, 04:46:45 pm »
When I do the measurement like this the correct value appears almost in an instant. I don't exactly know what you mean by refresh rate, the time it takes to display the proper value in the proper range, or the updating of the bar graph.

Well, lets forget the bar graph for now.

Yes, my interest are for the time that it takes so to display the proper value , 30.000 & Low resolution.
The higher resolution are always the slower one.  
The difference that I had ask for you to find, could be smaller than a blink of the eye.
And so just forget about it .

About the 26.5 Volts ( high resolution activation ) , its not as good as I was hope for.
Also in Fluke ones  the voltage must drop about 4V lower than the 20 , so the high resolution to be active again.
And so there is no winner even from this aspect, that at list it matters to me.

Well even if plain numbers, are not that important for the most of the people,
they are important when you actually compare things.

But we will have the opportunity to speak about that,
at the proper thread , when Dave manages to finish the review .

And I will only confirm too, that the people of Agilent, are up to this issue that happened to Dave, as we speak.

Personally I would love to had a tour on their facilities in Malaysia,
who knows , maybe the lucky one would ended to be our Dave.  

  



 
« Last Edit: May 21, 2011, 04:48:51 pm by Kiriakos-GR »
 

Offline saturation

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Re: EEVblog #170 - Agilent FAIL!
« Reply #51 on: May 21, 2011, 09:17:10 pm »
Hi Dave,

Had time to examine the 1272a in more detail and examine the issue you raised.  The closest I came to a problem that looks very close to yours has to do with the off/on switch.  Its better to see it that describe it.

One other thing that a bit scary at first is that the Low Z mode can sometimes show 100s Vac briefly, or for seconds, sometimes some kV levels too.  It was first shocking to see it, given it wasn't connected to anything.  I was able to duplicate that bug too and again trace it to the switch.

Although the DMM are connected to ~ 4Vdc here, but the issue occurs too with probes off.

They are both very reproducible.  Wiggling the switch too can cause it to happen when in the Low Z range.






« Last Edit: May 21, 2011, 09:34:59 pm by saturation »
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 Saturation
 

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Re: EEVblog #170 - Agilent FAIL!
« Reply #52 on: May 22, 2011, 02:38:19 am »
Thanks Saturation
Mine does similar stuff but not on the LowZ thing.
Almost certainly mechanical manufacturing tolerances between units causing this.
I've forwarded your videos onto Agilent, I think they have a very serious problem on their hands...
Will be interesting to see what they do here, because they have a lot invested in this new design with a big marketing push, and it's been out for some time now.

Dave.
 

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Re: EEVblog #170 - Agilent FAIL!
« Reply #53 on: May 22, 2011, 03:51:19 am »
My Mastech MS8226T has similar problems if the range switch is dirty. Some dielectric grease on the contacts seems to work well at preventing the problem.

At work, I solved a problem with some Agilent data acquisition multimeters they were using in an automated test setup. The problem was that the meters would often lose the connection to the control PC, especially if they were used with USB hubs. A firmware update fixed that. (I initially thought it was a bad hub or USB controller, so I switched out the hub several times and even swapped out the entire PC. Then it dawned on me to try using the latest drivers instead of the ones provided with the test distribution and that's when I found the firmware update.)
Cryptocurrency has taught me to love math and at the same time be baffled by it.

Cryptocurrency lesson 0: Altcoins and Bitcoin are not the same thing.
 

Offline Kiriakos-GR

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Re: EEVblog #170 - Agilent FAIL!
« Reply #54 on: May 22, 2011, 08:43:51 am »
Almost certainly mechanical manufacturing tolerances between units causing this.

Dave.

I can only agree , this is why some companies has specific notes about how to Reassembling the Meter,
in their own calibration lab ...

Example: 27 II/28 II Digital Multimeters Calibration Information ( Page 23 )
You need an special screwdriver with torque control !!   
 

Offline saturation

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Re: EEVblog #170 - Agilent FAIL!
« Reply #55 on: May 22, 2011, 11:01:06 am »
You're welcome.  It makes the u1272a a better meter, since I know were the bug is coming from.  However, given the marketing around this meter, its a bit ironic.

One last major issue, why my u1272a was out of cal with a valid Agilent cal certificate.  I received this DMM factory fresh.  I maintain my own 10.000 00 VDC standards and keep my instruments at tight tolerances, as pictured.  The first image is 10VDC, the second is 1004.7 VDC.

I'm 90% done with performance testing and can't find significant faults.  This one remained annoying so finally I calibrated the 1272a yesterday.  Its hard to prove to Agilent if they asked for the DMM back for examination because once its calibrated the problem is gone, so the pictures have to tell the story.  But I've let it linger for almost 3 weeks and I can't field test this further with it reading off.

Calibrating this meter is the easiest I've ever done.  

You can calibrate just a single range without having to adjust all the meter's other functions, which the Fluke 87V has you do.  You can jump into calibration mode at any time, in the middle of a measurement, just turn the DMM on, and hold the blue and orange buttons down for over 1 second, then enter the password.  It requires many keystrokes thereafter to go through the menus so that its very unlikely you'll accidentally calibrate this DMM, just turn it off without completing a single range sequence will abort the adjustment.

If you have to calibrate every range to adjust just one range like a Fluke 87V, its very time consuming if you don't have an automated calibrator.  To the Fluke's credit, I've never had to adjust it ever though.






Thanks Saturation
Mine does similar stuff but not on the LowZ thing.
Almost certainly mechanical manufacturing tolerances between units causing this.
I've forwarded your videos onto Agilent, I think they have a very serious problem on their hands...
Will be interesting to see what they do here, because they have a lot invested in this new design with a big marketing push, and it's been out for some time now.

Dave.
Best Wishes,

 Saturation
 

Offline Kiriakos-GR

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Re: EEVblog #170 - Agilent FAIL!
« Reply #56 on: May 22, 2011, 12:36:34 pm »
This one remained annoying so finally I calibrated the 1272a yesterday.  Its hard to prove to Agilent if they asked for the DMM back for examination because once its calibrated the problem is gone, so the pictures have to tell the story.

About the ethical and legal part of the story, you had no authorization to act like that.

Even so, my own personal opinion is that the few words in text and some photos , had zero creditability.
Especially when it is an direct public accusation, coming  from an anonymous source.  
I would trust Dave or Alm  about subjects related to quality control and multimeters .
But I would not trust any one, who acts like you did .

Keep up the good work.  
 
 

Offline elCap

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Re: EEVblog #170 - Agilent FAIL!
« Reply #57 on: May 22, 2011, 02:20:21 pm »
I noticed that if the switch is a little off (close to or between two settings) the warning for wrong connection of the probes does not work. When this happens the meter looks to be working, nothing strange on the display but there is no response from the buttons (for instance the backlight cannot be turned on). If you move the probes for correct connection, without touching the switch, it sure does measure as it should.
So to be safe it's good practice to always try to turn on the backlight after each operation of the switch. ::)
I don't know how likely this is to happen in really life but I guess Mr Murphy will make sure it does happen!
 

Offline Kiriakos-GR

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Re: EEVblog #170 - Agilent FAIL!
« Reply #58 on: May 22, 2011, 02:55:52 pm »
Hello elCap ..

You are correct, in the real life you worry more for your own Boss ,
and less about Mr. Murphy, or your Multimeter.. :D  
« Last Edit: May 22, 2011, 02:57:42 pm by Kiriakos-GR »
 

Offline gobblegobble

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Re: EEVblog #170 - Agilent FAIL!
« Reply #59 on: May 23, 2011, 12:06:07 am »
I've had 1 major issue, it was shipped with the Vdc range out of cal.  Its running at 0.11% at all ranges while its rated at 0.05%.  Its easy to fix properly but its a fairly odd finding in a new DMM with a valid certificate.

That's not easy to fix for everyone, and if you think from a another perspective, the calibration is about half of the darned thing's price: it definitely should be in cal with a traceable cal cert it's shipped with. >:(
 

Offline Kiriakos-GR

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Re: EEVblog #170 - Agilent FAIL!
« Reply #60 on: May 23, 2011, 02:11:53 am »
Blaming the DMM about be out of calibration it is easy to do..
Lets see if there is any smart one among us , so to blame the Fluke calibrator, who actually did the calibration to this DMM.  

1) Agilent does not make calibrators .

2) Before the DMM gets calibrated , it passed from QC inspection. 

3) Got calibrated , the calibrator print the calibration certificate.

4) The boys of Agilent with confidence , sent this DMM for distribution.

Pick up a target , any one you like , and shoot it.  

 
« Last Edit: May 23, 2011, 02:23:28 am by Kiriakos-GR »
 

Offline saturation

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Re: EEVblog #170 - Agilent FAIL!
« Reply #61 on: May 23, 2011, 12:22:38 pm »
Yes, that's one reason I did nothing for so long, but no one else here reported it, so I presume its fairly rare. Agilent did not request it back so I have to move on with testing.

But since the DMM was given to me to keep, and I am supposed to use it as a working meter, I can't do more with it reading as is.  The DMM logs all calibration changes, and on receipt it began as zero adjustment count.  There are still more issues that will be feedback to the company directly first before I post, but the one's on this thread are major ones; other people who bought/own this meter and maybe using it for real work should be aware of the major issues because it will impact usability immediately.  Other issues are not major but still reflects on quality control.

Now that the meter is reading well, I can put it through what its intended to do in the field.


I've had 1 major issue, it was shipped with the Vdc range out of cal.  Its running at 0.11% at all ranges while its rated at 0.05%.  Its easy to fix properly but its a fairly odd finding in a new DMM with a valid certificate.

That's not easy to fix for everyone, and if you think from a another perspective, the calibration is about half of the darned thing's price: it definitely should be in cal with a traceable cal cert it's shipped with. >:(
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 Saturation
 

Offline shadowless

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Re: EEVblog #170 - Agilent FAIL!
« Reply #62 on: May 23, 2011, 03:24:10 pm »
Not everyone has access to calibration equipment to resolve this issue.  A calibration cert cames with the Agilent DMM and you would expect the meter to be in proper order not just in the level of calibration but also function accurately to spec.


 

Offline Kiriakos-GR

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Re: EEVblog #170 - Agilent FAIL!
« Reply #63 on: May 23, 2011, 06:26:12 pm »
Not everyone has access to calibration equipment to resolve this issue.  A calibration cert cames with the Agilent DMM and you would expect the meter to be in proper order not just in the level of calibration but also function accurately to spec.

No one said that this calibration " Issue " will be something that every one will face , when he gets this model.
If any one say something like that, he must be nuts ..

I did an comparison of the serial number of the DMM that  Tronixstuff had , with the one that Dave got ,
it looks that there is out there , hundreds of thousands of such units.
And also the Google spying monster , its totally clean from complains too.  :)

Not to say, that this expensive DMM , has as target mostly professionals,
and those people, are capable enough to contact the company and resolve any issues.
And they do have, more than one DMM to work with !!
So to send back the possibly problematic one, even just for inspection.

All those contracts about check and calibration between the maker of the DMM ,
and the large factories or private companies (that are the customers) ,
serves exactly this purpose .
No matter what , you are covered .

The single consumer just uses the warranty plan , it simple and effective.

And I am here and writing all those words as an reaction,
because I have sense in the atmosphere unjustified exaggerations.
That's all.

  
« Last Edit: May 23, 2011, 06:28:30 pm by Kiriakos-GR »
 

Offline shadowless

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Re: EEVblog #170 - Agilent FAIL!
« Reply #64 on: May 23, 2011, 08:03:51 pm »
A new product should simply not has this fault period.

On the contrary, I think your reaction is exaggerated.
 

Offline Kiriakos-GR

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Re: EEVblog #170 - Agilent FAIL!
« Reply #65 on: May 23, 2011, 11:37:13 pm »
A new product should simply not has this fault period.

There is no chance to have an dialog , with someone who uses the word "period"
And so I will save my words too.  :)

 

Offline gobblegobble

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Re: EEVblog #170 - Agilent FAIL!
« Reply #66 on: May 24, 2011, 02:39:06 am »
Yes, that's one reason I did nothing for so long, but no one else here reported it, so I presume its fairly rare.
I have a grainger-discounted U1252A which came with a cal cert, but only way I could think of to verify validity of that is to have it re-calibrated and that would set me back more than what I paid for the meter itself. :(

Makes one to think twice about the measurement confidence Dave touts about.
 

Offline saturation

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Re: EEVblog #170 - Agilent FAIL!
« Reply #67 on: May 24, 2011, 06:36:04 am »
One day your meter may get drift off calibration, but you never know when.  If you have only one DMM, you won't be able to confirm a critical reading or do a spot check, because you have no comparison. 

I have that 1252a too from grainger.com and its faultness, except for some peculiarities in its megaohm resistance reading; its too sensitive and picks up quite a bit of EMI or static, could use an optional filter section.   To confirm its accuracy I just did to it what I did to the 1272a against my other meters.

 

Yes, that's one reason I did nothing for so long, but no one else here reported it, so I presume its fairly rare.
I have a grainger-discounted U1252A which came with a cal cert, but only way I could think of to verify validity of that is to have it re-calibrated and that would set me back more than what I paid for the meter itself. :(

Makes one to think twice about the measurement confidence Dave touts about.
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 Saturation
 

Offline gobblegobble

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Re: EEVblog #170 - Agilent FAIL!
« Reply #68 on: May 24, 2011, 12:27:06 pm »
One day your meter may get drift off calibration, but you never know when.  If you have only one DMM, you won't be able to confirm a critical reading or do a spot check, because you have no comparison. 

I have that 1252a too from grainger.com and its faultness, except for some peculiarities in its megaohm resistance reading; its too sensitive and picks up quite a bit of EMI or static, could use an optional filter section.   To confirm its accuracy I just did to it what I did to the 1272a against my other meters.

I can compare it to other meters to know whether it's all out of whack, but it's not really a feasible way to determine if it's spot on as when comparing it to 0.5% accuracy meters I can't really know for sure even when I can get my hands on dozen meters to compare it with.

I suppose getting more meters of similar accuracy could be warranted, but no-one I know has need for such and I certainly don't have plans to buy several myself. :D
 

Offline shadowless

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Re: EEVblog #170 - Agilent FAIL!
« Reply #69 on: May 24, 2011, 07:32:05 pm »
Agilent give calibration cert for a purpose, wonder if the cert does not actually certify anything then what's the point? Is that just a marketing gimmick?

A product that does not perform to spec new is a faulty product. There is no discussion necessary on this issue. With or without your own calibration capability i think this is not acceptable.
 

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Re: EEVblog #170 - Agilent FAIL!
« Reply #70 on: May 24, 2011, 10:18:49 pm »
I have that 1252a too from grainger.com and its faultness, except for some peculiarities in its megaohm resistance reading; its too sensitive and picks up quite a bit of EMI or static, could use an optional filter section.   To confirm its accuracy I just did to it what I did to the 1272a against my other meters.
I've seen this in other meters. I've assumed this is due to the very low current at high resistances (because of the limited compliance of the internal current source in the DMM). Induced current will influence these measurements, not sure how filtering is going to help, apart from the standard CMRR/NMRR stuff. Guarding the connections should help, but is somewhat impractical in a hand held meter. Maybe the other meters that are less sensitive use a higher test current/compliance or have better CMRR/NMRR?

If a meter calibrated by Agilent is found out of spec within the calibration interval, something is either wrong with the stability of the meter, or there's a serious issue with their calibration equipment/procedure.
 

Offline Kiriakos-GR

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Re: EEVblog #170 - Agilent FAIL!
« Reply #71 on: May 24, 2011, 10:34:08 pm »
Hi shadowless , in your post above you just repeating your self for an second time in the row .

Do you expect some sort of reaction from some one ?
If Saturation wishes to sell to you the specific unit that he owns , do not buy it.
Our topic is about the trouble that Dave had with his own sample .
I do not act as moderator !! I am just ask questions so to find out what is really hidden at the back of your head.

The 98% of every one who reads this topic , had buy an DMM with out calibration certificate.
And its not a crime to return a multimeter back to the maker , because there is something wrong with it.

As long there is not printed on the carton box of it, any questionable ancient quality standard's like " Zero defects " or "Six Sigma" ,
its just a product for consumers , and that's all about it.  
If you have never return a product in your life , you are just lucky so far , do no expect this luck to last for ever  :)
Nothing does .
 



 
 

Offline FreeThinker

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Re: EEVblog #170 - Agilent FAIL!
« Reply #72 on: May 24, 2011, 11:06:20 pm »
The way you are defending Agilent would make you think they had given you a free meter or somthing ??? :)
Machines were mice and Men were lions once upon a time, but now that it's the opposite it's twice upon a time.
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Offline Kiriakos-GR

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Re: EEVblog #170 - Agilent FAIL!
« Reply #73 on: May 24, 2011, 11:52:20 pm »
The way you are defending Agilent would make you think they had given you a free meter or somthing ??? :)

I was prepared even for an such of reply too ..  ;D  ;D  ;D  ;D

This specific U1272A it will be the first one , that will enter in the Greek borders,
not even the main distributor of Agilent in Greece does not have actually touch one yet.

Their " Mix up " had cause almost damage to me, I am in danger to loose my face.
I have write to all of my friends about this subject. In the Greek forum ( about electronics) that I am member too.
There is 2500 views in the  "Reads counter" and five pages with messages with congrats about me,
and still , I have to write excuses for almost 30 days , about what happened with it.

You are correct when you implying that I am in love with Agilent ,
but only if you are saying it as joke, and laugh about it , as you did ..  ;)


 

 

  
« Last Edit: May 24, 2011, 11:55:58 pm by Kiriakos-GR »
 

Offline shadowless

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Re: EEVblog #170 - Agilent FAIL!
« Reply #74 on: May 25, 2011, 03:19:50 am »
You don't even have one in your possession to defend for. Saturation from posting his real experience.  I post twice and it still doesn't seems to register need i say more.
 


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