Author Topic: UNI-T model UT-70D  (Read 15794 times)

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Offline mzacharias

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Re: UNI-T model UT-70D
« Reply #25 on: May 30, 2011, 11:29:29 pm »
 

Offline mzacharias

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Re: UNI-T model UT-70D
« Reply #26 on: May 31, 2011, 02:18:00 am »
I tested exactly as I have seen Dave and others test meters, with a variable DC supply instead of a battery. Also, I rebooted and re-connected the DC supply to the UT-70 many times during the test, and there were intervals as well. I have allowed for the possibility of a testing error - see my original post on the subject - but I see no reason to change my conclusion at this time. Also, don't forget that there was error showing in the voltage reading even when no Low-Battery indication was evident - it is my position that this should never happen.
« Last Edit: May 31, 2011, 11:23:07 am by mzacharias »
 

Offline saturation

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Re: UNI-T model UT-70D
« Reply #27 on: May 31, 2011, 11:36:13 am »
Thanks for the video and the tests; always important to performance test a new device before adding it to your test bench ... i.e., test its ranges and accuracy in this case.

I've never tested the low bat indicator though, so I'll add that to my list of todos, most reputable makers and the ease of designing such an indicator [ even the lowly $8 LCD panel meter can do it properly]  often makes that function overlooked, but your video is surprising.

Even if you have have a one-off defect, I'd wonder about using this meter long term if the accuracy falters when the battery is low, and the low bat indicator is unreliable.

  
Still working on a review but there is a potential EPIC FAIL on the UT-70D. I was testing the point at which the low-battery indicator came on. Initially I was encouraged that the indication triggered at 6.2 volts. This would indicate a very good useful battery life on this model. On the second test, the indicator came on at 5 volts! After that it wouldn't come on at all! The display dropped out at about 3.3 volts. Naturally I was concerned, so I repeated the test several times but the indicator never came on again. I then tested at what level the UT-70D accuracy started to suffer and discovered it began to lose accuracy at about 7 volts, although not by more than a couple tenths of a volt until the "battery" was under about 6 volts. I suppose there could have been some issue with my methodology versus the UT-70's power monitoring which isn't obvious, but my test was pretty simple. Time will tell, I guess. Will keep you all posted.
« Last Edit: May 31, 2011, 11:46:17 am by saturation »
Best Wishes,

 Saturation
 

alm

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Re: UNI-T model UT-70D
« Reply #28 on: May 31, 2011, 09:26:19 pm »
Does it check the battery condition only at boot ? 
That would be a definite FAIL. What if the battery runs out while the meter is powered on? Low battery is a safety issue if it causes the meter to be inaccurate (which it appears to do), so it should check almost as frequently as it samples the input value.

And avoid the FAIL description ,  because currently you are the one who failed to test properly the device.
It's not your baby, just some random faceless test equipment manufacturer that makes some low to mid-end products. You've failed to present any convincing counterarguments (your only argument was that they might have screwed up the product design in some other way), so my money is still on the person presenting actual data.

This is my opinion, and nothing will come out by arguing about it .
Yeah, trying to be objective and keeping an open mind are overrated.
 

Offline Kiriakos-GR

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Re: UNI-T model UT-70D
« Reply #29 on: May 31, 2011, 10:05:44 pm »
Ok alm if you wish hard game , you will have it .  >:(

I can not stay silent when every amateur try's to mimic what Dave does in his blogs.

It looks as cheap copy in my eyes , and basicaly what matters most to me, are that everything that gets posted,
to be an true gain as information , and not misinformation.

Only UNI-T in this case holds the information , about the time interval that the multimeter uses for the battery check.
The battery check was never an such critical information , to to be checked every second .

Even Dave or any reviewer does not have the spesific information about this time internal check.
Only the programmer who made the firmware does .

And right now I do not see any UNI-T FAIL , I just watch Americans who failed to test properly one multimeter.     

 

Offline mzacharias

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Re: UNI-T model UT-70D
« Reply #30 on: May 31, 2011, 10:38:19 pm »
More than once I have seen marginal 9 volt batteries decline in voltage over the course of a few seconds or a few minutes. I would expect most of here have seen this also. For the low-battery indicator to fail to come on in this situation is not acceptable. I tested the meter every which way; this can plainly be seen in the video. I firmly believe that if there were some way that it were actually operating correctly, I would have found it. That is all I have to say.
 

Offline Kiriakos-GR

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Re: UNI-T model UT-70D
« Reply #31 on: May 31, 2011, 11:39:15 pm »
Well if the question become as : How I properly do it .

I have the answer .

Buy this device .. https://www.eevblog.com/forum/index.php?topic=448.msg6650#msg6650

With it , separate your batteries , by their charge level  (0 - 100% )

As long you have 10 batteries with different capacity  (0 - 10% - 20% - 30%  ----- 100% ) of charge .
Insert them one by one , and inspect the behavior of the battery indicator on the DMM .

That's how you will do it .  

But you did not ask to learn about the how-to  !!
You acted by your own way .  
I do that too, but when I have no one to talk to .
You have ...  :)


 

Offline mzacharias

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Re: UNI-T model UT-70D
« Reply #32 on: June 01, 2011, 12:15:29 am »
Well if the question become as : How I properly do it .

I have the answer .

Buy this device .. https://www.eevblog.com/forum/index.php?topic=448.msg6650#msg6650

With it , separate your batteries , by their charge level  (0 - 100% )

As long you have 10 batteries with different capacity  (0 - 10% - 20% - 30%  ----- 100% ) of charge .
Insert them one by one , and inspect the behavior of the battery indicator on the DMM .

That's how you will do it .  

But you did not ask to learn about the how-to  !!
You acted by your own way .  
I do that too, but when I have no one to talk to .
You have ...  :)




Now you are just being ridiculous. I know you love to argue, but this has gone beyond silly.
 

Offline Kiriakos-GR

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Re: UNI-T model UT-70D
« Reply #33 on: June 01, 2011, 12:22:33 am »
Thank you very much .. personally I think as bless to be called ridiculous by you.

Bye bye ...  :)

 

Offline mzacharias

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Re: UNI-T model UT-70D
« Reply #34 on: June 01, 2011, 12:26:53 am »
Thank you very much .. personally I think as bless to be called ridiculous by you.

Bye bye ...  :)



Good night, K!
 


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