DIY 34401A calibration

[Dr. Frank]

How the "adjusting" of the 34401A actually works?
Provided I've got 10V source and 10k resistor, and I want to "DIY adjust" my 34401A's 10V and 10k ranges.

I cannot find the details on the procedure, though. I do not want to start to play with the "Calibration" Menu items before having a good understanding what the meter would request me.. 

My current understanding is it will ask me to connect 10V (or 10k) and then to enter (via the front panel keypad) the "exact values", like "10.001.345V" or 9.999.887ohm".

Is my above expectation somehow correct?

Please get the service manual, 34401-90013.pdf
The calibration procedure is explained in great detail from page 76 onwards.
Remark: It is necessary to perform the zero calibration first!

Frank

[iMo]

I've seen that, not sure what it asks for, ie. in the point 5

5. Use ∨ to move down to the “parameters” level and then set the calibration value for the present input value.

Do you dial in the "your number", or you just select "10V" from a list?

[Dr. Frank]

that works exactly as the manual number entry of e.g. the Min/MAX, Null Value, etc., i.e. the default is 10.00000, then you select the digit by <> and then increase/decrease the value until it matches your references value.

Frank

[iMo]

And what could be the "spread" of the Vref, Rref you may dial in?

[Dr. Frank]

Sorry, RTFM! 

0.9 ... 1.1 Full Scale, where Full Scale is e.g. 10.00000 V

[HighVoltage]

Does anyone know, how is the internal wiring of Agilent's 34172A/B short block ?

After many years of looking out for the Agilent 34172A Calibration Short, finally one showed up and I was lucky to get it. This one came brand new in the original bag.

However, after opening it up, I was a little disappointed.
I did not expect a soldered wire inside.

But it seems this was good enough for Agilent at the time.

Well, at least now we know how it looks inside.

[HighVoltage]

I just hooked the 34172A short up to a warmed up 34410A in:

- 4W Ohm Mode
- 100 NPLC,
- Offset Comp. ON
- 100 Ohm range (lowest)

It started with 000.000,7 Ohm and took about 1 min to move to 000.000,0 and just sits there very stable.

[DC1MC]

How much for this gem of an Agilent technology     ?

Cheers,
DC1MC

[HighVoltage]

30 Euro including shipping for.

Well, new price was maybe 10 fold?
At least now we know how the Agilent metrology magic looks inside.

[tggzzz]

I just hooked the 34172A short up to a warmed up 34410A in:

- 4W Ohm Mode
- 100 NPLC,
- Offset Comp. ON
- 100 Ohm range (lowest)

It started with 000.000,7 Ohm and took about 1 min to move to 000.000,0 and just sits there very stable.

With OComp on, I would be worried if it didn't!

What is it like on DCVolts, Null off, Autozero on, 100NLPC ? With Stats on, you could see the min/max (and avg/std dev).

Yes, I like the 34410A's stats display; it often saves uploading to a computer for post-processing.

[HighVoltage]

With OComp on, I would be worried if it didn't!

Same display value with Offset Comp OFF
000.000,0 to 000.000,1

About 79 uOhm on average stats display.

[HighVoltage]

Here are some pictures of the original FLUKE short block for comparison.

[HighVoltage]

What is it like on DCVolts, Null off, Autozero on, 100NLPC ? With Stats on, you could see the min/max (and avg/std dev).

Yes, I like the 34410A's stats display; it often saves uploading to a computer for post-processing.

Yes, the stats display of the 34410A and 34411A are just perfect.

Voltage readings withe the AGILENT short installed:

- Average: 962 nV
- Max: 1,13 uV
- Min: 743 nV
- StdDev.: 85 nV

[HighVoltage]

Same Voltage readings withe the FLUKE short installed on the 34410A:

- Average: 668 nV
- Max: 850 nV
- Min: 508 nV
- StdDev.: 65 nV

[tggzzz]

My Agilent 34410A with the Bulgarian short was initially -1.14µV to +1.2µV.

After a few hours to stabilise, it was +0.56µV to +1.11µV, mean .85µV, std dev .08µV.

So, pretty similar to yours.