Our outdoor air temperature sensors contain a rugged RTD or thermistor sensor for high accuracy and long term stability for temperatures between -50C to +80C or a thermistor for ease of connection to certain control systems. This assembly's construction consists of a waterproof seal, a weather resistant shield and non-corrosive material to withstand all weather conditions. The cover of the sensor rejects solar heat for more accurate temperature measurements. The sensor has a 1/2" NPT female thread for conduit mounting or clamp-on installation.
Platinum RTD's are the most stable temperature sensors between -50 and 400C. They show almost no calibration drift with time. Their stability, wide temperature range and almost linear output make them the choice in demanding applications. Our standard RTD uses a 100 ohm thin film element to DIN 43 760 (IEC 751) with a tolerance of 0.3 deg C. We also supply thin film RTD's with a tolerance of +/- 0.1 C or 0.05 percent in values of 100, 500 and 1000 ohms.
NTC Thermistors are the most sensitive sensors known for temperature measurement from -50C to +150C. The temperature coefficient of thermistors can be as high as several percent per degree C. This means that lead resistance from installation of thermistors in remote areas has minimal effect on system accuracy. Since they are semiconductors they must not be exposed to temperatures near their maximum operating limits or they can drift out of specified tolerance. Our standard thermistor has a 10K resistance at 25C and a tolerance of +/- 0.2C. On request other calibrations and accuracies are available.
The construction of these sensors limits their operating temperature to -50...+70C.