Fast immersion thermistor

[maxwell3e10]

I needed a fast temperature sensor for water temperature control and compared a couple of promising thermistor models. I thought I'd share the results here. Vishay NTCAIMME3 is the winner, it has a time constant of 1.1 sec according to my measurements and is quite inexpensive for an encapsulated sensor. Amphenol CR1 is a bare chip coated with water resistant coating. But despite having a much smaller mass, it actually has a slightly slower thermal response.

[RoGeorge]

In my experience, thermocouples were the ones with the lowest thermal inertia.

[maxwell3e10]

It's hard to get mK temperature resolution with a thermocouple. And it would still need to be protected from corrosion in a liquid.

[thm_w]

Yeah bare thermocouple will easily corrode in water causing some unusual readings.
For some reason I used to think the normal thermocouples you get with a DMM could be immersed.