I’m not sure what the terminology is to search for, but I want to place a permanent temperature sensor post-shower-valve to measure the temperature of the mix leaving the valve so I can program a stepper motor to adjust the thermostatic temperature lever so we can control it from HA.
I can’t use an external surface sensor because the pipe is pex and it won’t be accurate.
The ones used to measure the coolant temp of a car’s engine are pretty accurate, since they need to adjust the engine management settings for proper operation.