RE: Where's the Heat? Blog #1

DAB — Tue, 26 Jul 2022 18:43:59 GMT

An interesting experiment.

I look forward to seeing your results.

Have you considered doing a site inspection with a thermal camera?

It might give you some heads up on heat source and sinks in the building.

RE: Where's the Heat? Blog #1

michaelkellett — Tue, 26 Jul 2022 09:13:40 GMT

Watch out for the goodness of the ADC on the Pi 2040 chip. From the datasheet it barely scrapes 8 bits (ENOB) . Microcontroller ADCs are often not as good as one hopes (I have scars and much experience of tying to linearise them in code, to prove it.)

I have a current experiment using thermistors to check the temperature of some devices under test. I'm using a Keithley DAQ 6510 measuring resistance in 4 wire mode, it gives a resolution of better than 1mK (milli degree kelvin). The plot is limited to 3 decimal places by the data processing.

I'm pleased to be able to show the 16mk instability in the temperature control system. (It's much better a bit further away from ambient.

Obviously you won't need the same performance with your set up but there is alot to be said for a single measuring point and wired multiplexing for confidence in compariung data from multiple sensors.