Fluke 343A repair

[bastl_r]

Hello
How much drift of the 15V reference voltage can realistically be expected during a few hours on a Fluke343 calibrator?
The temperature is approx. 25°C +/-1°.
Measurements are made with a K2002.

Greetings bastl_r

[bastl_r]

Renewed question about the drift of the reference voltage of my 343::
Is it normal that I find a difference of about 20µV on the min/max display after about 8 - 9 hours with the K2002?
So 14.999682xV and 14.999665xV.
This means a drift of approx. 1.1ppm. It feels like 20µV is too much, but 1.3ppm is still quite low for such a device.
Or is it?

regards bastl_r

[Rax]

Sorry, bastl_r, I no longer have one at my bench. Hopefully those that do will assess your condition.

[bastl_r]

Thank you for your answer.
I realise that the stability of any calibrator is finite and I am aware of the efforts being made to constantly increase it. However, the 20uV over 8 to 9 hours spontaneously seems a bit much to me.
But I would still be happy if I am wrong.

Greetings bastl_r

[unseenninja]

Thank you for your answer.
I realise that the stability of any calibrator is finite and I am aware of the efforts being made to constantly increase it. However, the 20uV over 8 to 9 hours spontaneously seems a bit much to me.
But I would still be happy if I am wrong.

Greetings bastl_r

I'm wondering if I'm seeing a similar problem which my 343A has developed. When I first received it, the calibration was poor, but the calibrator seemed stable, so I performed the adjustment procedure using my recently adjusted and calibrated Solartron 7061. After that, everything seemed fine and I didn't use the 343A for some time.

Recently, I became the owner of a Datron 1271. As part of checking its performance, I started a log of 10V from the 343A. To my horror, what used to be 10.00000V from the 343A was now more like 10.001V and is falling by a rate of 4ppm every 24 hours. I logged a whole week before I got bored of waiting for the curve to level out.



The specifications for the 343A are very conservative, but even worst case, this is outside of specifications. I have not yet had the time to investigate what the problem could be and have been following this thread with interest in your progress.

[bastl_r]

Thankyou for your response.
Your problem is an other than mine, i think.
Your log was on the outputvoltage.
My measurment was directly on the referencespannung(TP2). The voltage at this point oscillates over long periods of time by around 20uV around the mean value of approx. 14.999670V.
Your Problem, i think, is the chopperamp. Maybe the ageing capacitors in it.
Regards bast_r