Measuring internal temperature of a DMM

[enut11]

I have an HP3456A and note that it takes a very looong time to stabilise from cold, especially if I want to characterise another device. I think it is related to its internal temperature.

I purchased a simple thermometer that reads IN/OUT temperatures and has a probe on a 1m lead. I want to install this probe inside my HP3456A DMM and monitor the temperature rise from DMM cold start and compare the reading to a stable 10v Ref which has been on continuously for weeks.

I realise the best way would be to simultaneously log temp and volts but have yet to implement this. In any case it does not affect the validity of my question: Where is the best place in my HP3456A DMM to place the temperature sensor?
enut11

[Vgkid]

Your best bet would be to place it on the A20(analog) board. It is the one that is completely covered. I don't remember if it is on the top or bottom of the unit(been about a year since I have opened it up). For placement try the V-Ref board, or around u 200/500 which are the custom hybrid resistor arrays.

[Andreas]

Hello,

pay attention that you do not compromize the isolation of the floating part of the DMM.

In my K2000 it plays nearly no role where the temperature sensor is placed inside the DMM.
https://www.eevblog.com/forum/metrology/project-pimp-a-keithley-2000/msg1106832/#msg1106832

So I can place it on the earth referenced side.

with best regards

Andreas