I have a request to setup a monitoring temperature sensor for a industrial freezer , that is operating at -17 and -24 Celsius.
I have a Shelly 1PM + Addon with a DS18B20. The temperature sensor was working fine for 2 days, but the the readings are off the chart , occasionally it show -4 Celsius with is unrealistic.
Dos anyone have a recommendation for a temperature sensor that is working in a freezer. I can use also a ESP32 board if needed.
I’ve only used thermocouples. I favor esphome for these types of projects. There are components for both types. The max31856 platform is only for k type thermocouples.
In the first post the problem was you were getting -4 when the temperature was actually lower. The unit’s operates in the range of -17 to -24.
The graph you posted shows the temp is ranging from -14 to -24. The problem now is the last spike? The plot seems to show consistent rise in temp as opposed to it jumping up several degrees from one reading to the next. Is it possible someone opened the freezer?
no, the readings are from 23:00 until 7:00 next day. During the night no one is open the freezer.
I don’t think the freezer loses that much energy in this interval.
Now I ordered:
Adafruit Universal Thermocouple Amplifier MAX31856 Breakout Module K-Type Thermocouple with Insulated Temperature Resistant Wire and Stainless Steel Tip