blaplante
Well Known Member
I'll fess up, I'm a EEng, and I'm not sure how this could happen, but maybe someone here knows.
Is it possible for a thermocouple sensor to fail / intermittent in a way where it reads HIGH? I know a thermocouple produces a tiny voltage, and so the typical failure mode is an open, and it should read low. Or it shorts to ground, I'd expect the same.
Scenario was - older JPI monitor. Oil Temp reads sometimes absurdly high - like over 400F. Obviously not possible without smoking the oil, and the oil has no burnt smell. Yes plane is currently grounded. JPI uses thermocouples for all temp sensing.
the EGT/CHT is all reading normally.
Is it possible for a thermocouple sensor to fail / intermittent in a way where it reads HIGH? I know a thermocouple produces a tiny voltage, and so the typical failure mode is an open, and it should read low. Or it shorts to ground, I'd expect the same.
Scenario was - older JPI monitor. Oil Temp reads sometimes absurdly high - like over 400F. Obviously not possible without smoking the oil, and the oil has no burnt smell. Yes plane is currently grounded. JPI uses thermocouples for all temp sensing.
the EGT/CHT is all reading normally.