Does anyone know what sort of sensor is used in these cheap and cheerful LCD thermometers?
https://www.amazon.co.uk/dp/B0BK8SVW1P
Partially for curiosity, but also I have a number that don't work so am looking a letting my 10yo play with them and an Rpi so would be best that I know what they are first. They could be an 10K NTC thermistor for example.
Sensor type
Re: Sensor type
I've actually got one of these so cracked it open for a look. It's only marked RT on the board.
Put a multimeter across it and it was 12.5k ohm at 20c, rising to about 24k ohm in a glass of ice water if that helps any?
Put a multimeter across it and it was 12.5k ohm at 20c, rising to about 24k ohm in a glass of ice water if that helps any?
Re: Sensor type
I remember having some of them as a child myself, from maplin I would think. No Internet shopping then. I will have a look as I'm certain I still have one in a box of old childhood toys.
85no 58mm solar thermal tubes, 28.5Kw PV, 3x Sunny Island 5048, 2795 Ah (135kWh) (c20) Rolls batteries 48v, 8kWh Growatt storage, 22 x US3000C Pylontech, Sofar ME3000's, Brosley wood burner and 250lt DHW
Re: Sensor type
Pretty sure you are correct, the "sensor" is a 10k (ish) NTC. I bought a load a few years back and have a couple of defunct ones and the sensors measure just over 10kOhm at around 20 deg C & drops to around 1kOhm at approaching 100 deg C. Should be pretty easy to check/calculate the B value and then plumb some numbers in the code to make a working Thermometer on a RPi.