Author Topic: Bunch of keysight U1252B meters around  (Read 85549 times)

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Online cncjerry

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Re: Bunch of keysight U1252B meters around
« Reply #200 on: February 18, 2017, 09:44:06 am »
Glad everyone is enjoying the meters. Instead of buying another I gave mine a good cleaning...

Has anyone figured out how to calibrate the meter? 

Also, what is the highest capacity battery that can be installed in the meter while maintaining the charging system?  Or is there an external charger that would allow me to keep a battery on trickle while using another that can then be swapped in? I saw the powered posts.

Thanks
 

Offline bitseeker

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Re: Bunch of keysight U1252B meters around
« Reply #201 on: February 18, 2017, 10:29:34 am »
I have not seen info about a maximum capacity for the rechargeable battery, just the two supported voltages. The only things that come to mind that could occur should you get one that has too much capacity is that (1) the charging circuitry could be overworked from running too long or, more likely, (2) an overcharge timer would terminate the charging cycle.

I don't know for sure that there is a charge cutoff timeout, but there typically is one for NiMH chargers in case the delta V or delta T sense doesn't trigger.
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Offline unimorpheus

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Re: Bunch of keysight U1252B meters around
« Reply #202 on: February 18, 2017, 11:26:34 am »
I have not seen info about a maximum capacity for the rechargeable battery, just the two supported voltages. The only things that come to mind that could occur should you get one that has too much capacity is that (1) the charging circuitry could be overworked from running too long or, more likely, (2) an overcharge timer would terminate the charging cycle.

I don't know for sure that there is a charge cutoff timeout, but there typically is one for NiMH chargers in case the delta V or delta T sense doesn't trigger.

I see there are 9.6V Ni-MH batteries available but I stuck with the high cap 8.4V I am not sure the built-in charging system could charge the 9.6V to full cap. The  documentation does not address this configuration.
 

Offline bitseeker

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Re: Bunch of keysight U1252B meters around
« Reply #203 on: February 18, 2017, 12:07:45 pm »
Yeah, I'm not sure. With an 8.4V battery, it's at approximately 10-11V when full.
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Online cncjerry

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Re: Bunch of keysight U1252B meters around
« Reply #204 on: February 18, 2017, 03:47:07 pm »
Not to go off on a tangent, but I wonder why we can get 2800mAH out of a 1.2V cell but only 300mAH out of an 8.4V cell.  I would think we should get 400maH but that is only the mathematical coincidence.

I saw those batteries and I have a charger I guess that will work, so I am going to get two and leave one on the charger all the time.
 

Offline kgharibyan

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Re: Bunch of keysight U1252B meters around
« Reply #205 on: February 18, 2017, 04:22:41 pm »
Received mine, cal is Dec. 2015, nice item


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Offline FlyingHacker

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Re: Bunch of keysight U1252B meters around
« Reply #206 on: February 18, 2017, 07:00:54 pm »
Not to go off on a tangent, but I wonder why we can get 2800mAH out of a 1.2V cell but only 300mAH out of an 8.4V cell.  I would think we should get 400maH but that is only the mathematical coincidence.

Calculate the miliWATT hours and I think you'll have your answer.

You could also use lithium rechargeable 9V batteries, though you can't use the built in charger...
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Offline Gandalf_Sr

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Re: Bunch of keysight U1252B meters around
« Reply #207 on: February 18, 2017, 09:09:47 pm »
Not to go off on a tangent, but I wonder why we can get 2800mAH out of a 1.2V cell but only 300mAH out of an 8.4V cell.  I would think we should get 400maH but that is only the mathematical coincidence.

Calculate the miliWATT hours and I think you'll have your answer.

You could also use lithium rechargeable 9V batteries, though you can't use the built in charger...
To add to this.  The 8.4 volt battery has 6 x 300mAh cells inside it; you're trying to compare that to one 2800mAh cell.  Depending on the manufacturer, cells can have different capacities, obviously bigger cells have bigger capacities but better manufacturers get more mAh from the same size cell.  'Normal' rechargable 8.4 volt (6 x 1.4 volt) batteries in the PP9 format are only 175 mAh but the the Powerex brand claims to give you 300 mAh plus they claim a much longer shelf time (lower internal discharge).

As FlyingHacker has already said, work out the power using P = V x A.  A single cell NimH rated at 2800 mAh gives 1.4 x 2800 = 3920 mWh or 3.92 Wh, the Powerex 8.4 v, 300 mAh battery should give 8.4 x 300 = 2,500 mWh or 2.5 Wh.
 

Offline Gandalf_Sr

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Re: Bunch of keysight U1252B meters around
« Reply #208 on: February 19, 2017, 12:40:11 am »
My tracking says "out for delivery"  :-+
 

Offline FlyingHacker

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Re: Bunch of keysight U1252B meters around
« Reply #209 on: February 19, 2017, 03:38:22 am »
As FlyingHacker has already said, work out the power using P = V x A.  A single cell NimH rated at 2800 mAh gives 1.4 x 2800 = 3920 mWh or 3.92 Wh, the Powerex 8.4 v, 300 mAh battery should give 8.4 x 300 = 2,500 mWh or 2.5 Wh.

Yep. So they are close. You would think the 9V has more volume and ought to have more power, but I think this is due to two factors: A) With the higher voltage the 9V requires multiple internal cells, and thus has more empty space B) Supply and Demand dictates that a lot more research be done into AA and AAA sized batteries, as they are much more ubiquitous.
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Offline Luap2

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Re: Bunch of keysight U1252B meters around
« Reply #210 on: February 19, 2017, 02:05:25 pm »
Have Had mine a week only thing I see on the down side is a small blemish on the screen and needing a new Battery. I can live with those 2 very small thing no problem.
 

Online mtdoc

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Re: Bunch of keysight U1252B meters around
« Reply #211 on: February 19, 2017, 04:52:01 pm »
Have Had mine a week only thing I see on the down side is a small blemish on the screen and needing a new Battery. I can live with those 2 very small thing no problem.

Mine has a very small - about 1 mm diameter - blemish on the outer piece of plastic overlying the lcd screen.  It's in the top right quadrant - above the digits and it doesn't really bother me but I'm going to see if I can buff it out with some Novus plastic polish.
 

Online cncjerry

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Re: Bunch of keysight U1252B meters around
« Reply #212 on: February 19, 2017, 06:14:44 pm »
Mine, which wasn't one of these, has two little dots on the display. I would say the entire defect is less than a mm.
 

Offline Gandalf_Sr

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Re: Bunch of keysight U1252B meters around
« Reply #213 on: February 20, 2017, 12:06:00 am »
Mine arrived yesterday, about 3 hours after I'd left for 8 days away.  The blemishes and minor screen defects that everyone seems to be finding make me I wonder if these are seconds?  I don't mind for the price but they are being sold as 'new'.
 

Offline PTR_1275

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Re: Bunch of keysight U1252B meters around
« Reply #214 on: February 20, 2017, 02:31:33 am »
Mine had a cal certificate from 2015 and I was worried about the screen cover because there were a few marks under the screen protector. Normally I leave screen protectors on, but I removed this one and gave the screen a wipe with my finger and the mark was gone.

There was no doubt in my mind that mine was new, everything looked as I would expect it to come from the factory.

I bought a case from RS for it to protect it a bit when not being used (this is my first new handheld meter and I've recently gotten cases for all my flukes too). I am not a fan of the leads / probes that come with the meter so I've put a spare of my TL75 fluke leads in the case and put the keysight set in my spares drawer. I much prefer the fluke leads (or any that don't have banana plugs at both ends that you plug the pointy probe into) as they are quicker to get out of the case and use.
 

Offline FlyingHacker

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Re: Bunch of keysight U1252B meters around
« Reply #215 on: February 20, 2017, 04:13:14 am »
Mine had no blemishes at all. Seemed new, but older stock, cal late 2015.
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Offline Gandalf_Sr

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Re: Bunch of keysight U1252B meters around
« Reply #216 on: February 21, 2017, 04:50:32 am »
I'm on the fence about buying the U1117A Bluetooth-IR adapter, at $100 it's half the price of the meter.

It's all in how you look at it. Alternatively, you saved more than the cost of a U1117A, so buying one is practically free. Imagine if you had paid regular price for the DMM and then had to shell out another $100. ;D
I gave in and ordered a U1117A today from Allied Electronics, it was just over $100 with shipping.  I like the feature of a free App for my phone and I can also link it to my workbench PC using Bluetooth.

My U1252B is sitting unopened at my neighbor's house.  I am sitting in my cruise ship room in the Caribbean, it's an enormous ship, 5 times bigger than the Titanic according to onc article I read today - it's called The Allure of the Seas and the internet service is amazingly good.  I get back next Sunday (the 26th) when my U1117A should also have arrived, I'll report cal date and condition then.
 
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Offline sdouble

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Re: Bunch of keysight U1252B meters around
« Reply #217 on: February 21, 2017, 09:01:24 am »
mine got shipped 4 days after the (paypal) money transfer occured. It 's currently over the ocean, slowly reaching its new country : france
 
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Offline RGK

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Re: Bunch of keysight U1252B meters around
« Reply #218 on: February 22, 2017, 02:37:56 pm »
Bought & paid 2/12.
Left origin post office 2/16 with 2/18 expected delivery.
Tracking ceased 2/17 while "in transit to destination".
No new tracking progress or delivery as of 2/21 late PM.
Seller is responsive, but nothing to do but wait at this point.

Waiting for toys is hard.

BK

 

Offline loxodes

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Re: Bunch of keysight U1252B meters around
« Reply #219 on: February 22, 2017, 03:51:49 pm »
Bought & paid 2/12.
Left origin post office 2/16 with 2/18 expected delivery.
Tracking ceased 2/17 while "in transit to destination".
No new tracking progress or delivery as of 2/21 late PM.
Seller is responsive, but nothing to do but wait at this point.

I'm in the same position. Bought and paid on 2/12, left the origin post office on 2/16, "in transit to destination" on 2/17, and nothing since then..
From what I understand, "in transit to destination" is an automated message if USPS hasn't scanned the package in over 18 hours...
 

Offline shteii01

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Re: Bunch of keysight U1252B meters around
« Reply #220 on: February 22, 2017, 08:33:48 pm »
Mine arrived yesterday.  Calibration certificates dated 2012 and 2013.

Ordered Feb 11.
Shipped Feb 16.
Arrived to local Post Office Feb 18.
Feb 20 was holiday, no delivery.
Delivered on 21.

USPS tracking was ok, I think.
 

Offline natman69

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Re: Bunch of keysight U1252B meters around
« Reply #221 on: February 23, 2017, 02:53:17 am »
My U1252B arrived today. It was calibrated in april 2014.
It has a label "Peerless Electronic Supplies, Louisville KY" on the box.
It's clear and unused.

I've registered it on Keysight web portal and it has only a month of residual warranty.

This is my first serious multimeter!
I've noticed that if I put the knob on ac voltage without a source signal the value on the screen isn't zero but it keeps oscillating on about 6mV.
Is it thermal noise? Is it normal? Is it due to old calibration?
Even in dc voltage the reading fluctuates on 0.1mV.

Tomorrow I'll try to do some real measurement "on the bench".

 

Offline iainwhite

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Re: Bunch of keysight U1252B meters around
« Reply #222 on: February 23, 2017, 03:11:21 am »
I've noticed that if I put the knob on ac voltage without a source signal the value on the screen isn't zero but it keeps oscillating on about 6mV.

Might possibly be the Low Pass Filter setting?
See Post #85
 

Offline PedroDaGr8

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Re: Bunch of keysight U1252B meters around
« Reply #223 on: February 23, 2017, 03:20:02 am »
My U1252B arrived today. It was calibrated in april 2014.
It has a label "Peerless Electronic Supplies, Louisville KY" on the box.
It's clear and unused.

I've registered it on Keysight web portal and it has only a month of residual warranty.

This is my first serious multimeter!
I've noticed that if I put the knob on ac voltage without a source signal the value on the screen isn't zero but it keeps oscillating on about 6mV.
Is it thermal noise? Is it normal? Is it due to old calibration?
Even in dc voltage the reading fluctuates on 0.1mV.

Tomorrow I'll try to do some real measurement "on the bench".
Entirely normal, remember it is a really high impedance input. This means it doesn't take much charge to register a voltage.

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Offline deepskyridge

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Re: Bunch of keysight U1252B meters around
« Reply #224 on: February 23, 2017, 08:02:14 am »
Glad everyone is enjoying the meters. Instead of buying another I gave mine a good cleaning...

Has anyone figured out how to calibrate the meter? 

Also, what is the highest capacity battery that can be installed in the meter while maintaining the charging system?  Or is there an external charger that would allow me to keep a battery on trickle while using another that can then be swapped in? I saw the powered posts.

Thanks

Here is a link to a Agilent document for the U1252B, it includes calibration procedures.

cp.literature.agilent.com/litweb/pdf/U1251-90036.pdf

Gary
« Last Edit: February 23, 2017, 08:03:50 am by deepskyridge »
 


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