0
\$\begingroup\$

I have an NTC Temperature Sensor thermistor connected to a PID Temperature Controller. The main use of this controller is to control the temperature of chemicals in a reactor.

Due to the environment of the chemicals in the reactor (low and high pH, acids, vacuum etc.) I want to insulate the probe of the thermistor.

Does anybody know a way to perform such an insulation?

\$\endgroup\$
  • \$\begingroup\$ So you want a thermally-conductive, chemically-inert (as much as possible) and robust coating on the thermistor. \$\endgroup\$ – ratchet freak Oct 6 '17 at 11:07
  • \$\begingroup\$ I think you want to say "protective coating" rather than "insulation." Insulation would be either electrical or heat. You seem to want to protect the probe from harsh chemicals rather than insulate it from temperature changes or insulate it electrically. \$\endgroup\$ – JRE Oct 6 '17 at 11:26
  • \$\begingroup\$ Teflon (PTFE), stainless steel, ... \$\endgroup\$ – Russell McMahon Oct 6 '17 at 14:40
1
\$\begingroup\$

Put it inside a silicone tube, fold the tube in half, make sure the open ends are outside the chemical reactor.

\$\endgroup\$
  • \$\begingroup\$ Nice tip! Would wrapping it with a Polyimide Tape work? \$\endgroup\$ – deadpixels Oct 6 '17 at 12:21
  • \$\begingroup\$ I'm not sure the tape glue would be friends with your chemicals, but you can always try... thermistors aren't very expensive... \$\endgroup\$ – peufeu Oct 6 '17 at 13:27
1
\$\begingroup\$

If you're working in a chemically harsh environment, you might want to consider acquiring a thermistor rated for those environments such as this one:

https://www.digikey.com/en/product-highlight/a/amphenol-advanced-sensors/cr1-harsh-environment-ntc-thermistor

It would be far easier, and save you time, money, and headaches. Otherwise, you're not just re-inventing the wheel, but now looking into stainless steel enclosures or ceramic coatings, which cost many tens of times more than the thermistor itself...

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.