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, 135kWh Rolls batteries, 52kWh Growatt storage GBLI 6532, 66kWh Pylontech US3000C, 43kWh DIY, 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.