Sensor makes life a tad easier

Dean Palmer reports on a new self-monitoring temperature sensor that means regular calibration is a thing of the past

A new self-monitoring temperature sensor has been developed that means users no longer have to be concerned with regular calibration. IFM Electronic's new 'TAD' series sensors use two different sensor elements that monitor each other in the process, ensuring that any sensor drift that develops is immediately detected and diagnosed. Cyclical or regular calibration (which offers no absolute security since the sensors used are only checked selectively) is therefore not required. If one element fails with the TAD sensor, the process continues, with the second measuring element working as a backup function. Using the diagnostic output of the sensor, possible error states are transmitted directly to the higher level controller. A 'failure warning' and 'switch off' threshold can be defined via the software. The devices provide a 4 to 20mA analogue signal enabling processing in any common controller. Temperature range is -10°C up to 150°C and the sensor is resistant to extremes of -25°C up to 170°C for short periods. The evaluation accuracy is 0.2K in the range of -10°C up to 100°C and 0.3K for 100°C up to 150°C. The sensor has an integrated adapter thread which enables hygienic connection to process adaptors. The shape of the probe and the high temperature range allows cleaning and sterilisation when mounted. The devices are fully sealed and the housing is made from welded stainless steel, which guarantees protection to IP69 K. This means the sensor reduces the build up of dirt and can be cleaned on all sides.