The duct sensor is used to measure the supply and return air temperature in HVAC systems. There are several sensor elements to choose from which guarantee compatibility with all popular DDC systems. There is a precision thermistor. The probes are epoxy sealed to prevent moisture from migrating in. Field calibration is not generally required. The standard probe length is 12 inch. Custom probe lengths, wire types and sensor elements are available for large OEM projects. Ask about our plastics & metal manufacturing capabilities for custom housings as well.