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Some old school instruments showing how it's done (HP 3325A and Fluke 8506a)

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SilverSolder:
It could be interesting to see the temperature inside the R2 A/D converter, as well as the temperature next to the resistor being tested?

Assuming the temperature in the lab moves a little bit, and drafts of air are switched on and off with the central heating (even if the temperature doesn't change, the amount of heat that is carried away does change)...  we may see some interesting correlations?

joeqsmith:
Yes, the whole setup (meter + resistor) drifted about 2ppm.   Guessing that mostly the meter.

I changed it over to a Vishay S series, 50 ohm 0.01% part. This particular part is a C material.   

http://www.vishaypg.com/docs/63001/63001.pdf

I just soldered it to a couple of copper strips and clamped the K-type sensor to it.   The meter was not zero'ed and it's reading a bit on the high side.  (50 +/-0.005 ohms  plus the meter's 0.003%+1.4).   Keep in mind also, this was a poor man's alignment.  I don't have the tools needed to do a proper job. 

It's been running like this for about 2 hours.    Normally I would toss a beach towel over it but like before, its just sitting out in the open.

SilverSolder:

I like the temperature sensor clamping arrangement! 

Might just have a similar "Thermal Probe Mounting Adapter, $673" somewhere here! :D

joeqsmith:
Those paper clips come in handy for all sorts of things.  Soldering, gluing, holding wires in place, mounting sensors...   

I don't think you will learn much from this test.  It's been running about 3.7 hours.  The temperature has continued to go up during this time about 1deg C.  The spikes I suspect are static discharges in the room.  You can tell when I was no where near the setup.   The measured resistance however has stayed relatively constant.   

I have a higher tolerance part that I would like to try and use with better mounting.   I plan to zero out the meter this time and see if it can actually get some numbers that are within the total tolerance.     I'll move the thermocouple to the center of the meter.

Some of the better handheld meters I've looked at measuring this part.   



 

SilverSolder:

The temperature swings look like a central heating system cycling - Do you have an oil or a gas furnace by any chance?


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