Measuring the ambient, or surrounding air temperature, is a fundamental driving parameter for many systems, including climate or environmental controls. Additionally, measuring surface temperatures can be a basis for controlling parameters used to maintain a system operating within normal limits. This sensor is equipped with an on-board NTC sensor to measuring the local ambient air temperature and can receive a plug-in NTC probe to measure remote air, surface or liquid temperatures. Suitable for monitoring systems within air-conditioning systems, cold water chiller plants, or for monitoring temperatures of heatsinks, computer boards, bearings and other machine elements.