I am currently building an etching tank set up with 25 watt aquarium heater, and air pump. A thermistor comparator circuit will control the heater.
I will be using sodium persulphate at 45c for the etchant.
I am going to waterproof the thermistor with heatshrink, is that suitable(is the sodium persulphate going to attack it.) or is there better stuff than heatshrink?
Haven't got any heatshrink to test unfortunately, going to get some.
Just thought about putting the thermistor in a test tube full of johnsons baby oil(mineral oil) and immersing that, but it probably has too slow response?
By the way sodium persulphate starts to decompose at 50c