Non-intrusive process fluid temperature calculation system

A process fluid temperature calculation system comprising;

• a first temperature sensor disposed to contact an external surface of a process fluid conduit to measure an external temperature of the process fluid conduit;
• a stem portion confingured to be operably coupled to the process fluid conduit;
• a second temperature sensor configured to be spaced from process fluid conduit, the second temperature sensor having a known thermal impedance relative to the first temperature sensor;
• measurement circuitry coupled the first and second temperature sensors;
• a microprocessor coupled to the measurement circuitry to receive temperature information from the measurement circuitry and to calculate a process fluid temperature output using a heat flux calculation;
• and
• a housing attached to the stem portion, the housing containing the measurement circuitry, the second temperature sensor and the microprocessor.