Q. How does the dual RTD element system of the TCC differ from a typical redundant RTD system?
A. Typically, dual RTD systems consist of two PTC (resistance increases with increasing temperature) RTDs. Likely, these elements come from the same producttion batch and have been exposed to the same operating conditions. The probability that both elements drift at the same rate is likely and therefore, any difference between their measurements is small. That means no alarm or warning is likely to occur.
The TCC's dual element system consists of a PTC and an NTC (resistance decreases with increasing temperature). Therefore, if drfit occurs, it will be in opposite directions. The integrated calibration check diagnostics will detect it and alert the user.
Q. How does the calibration check of the TCC compare to a Curie point calibration temperature sensor?
A. A Curie point calibration system uses a material that changes its physical state only at a single reference point. At that point, it evaluates the temperature it measures and adjusts it accordingly. The calibration check of the TCC evaluates the measured value accross the entire range of the sensor, -13...320 °F (-25...160 °C). With a Curie point calibration sensor, if the process temperature never reaches the calibration temperature, it is never checked.
Q. The TCC sensors do not have pushbuttons. How do I change the measuring scale or the drift warning and alarm limits?
Q. What do the different LED colors mean?
A. The LED of the TCC is green in normal operation. If the sensor detects a fault in the measurement, the LED changes to red. If the measured temperature drifts from the expected value, the LED changes to blue. Details on the output behaviors in these states can be found here.