The Testo 0615 5505 Clamp Probe is designed for measuring the surface temperature of pipes (diameters from 0.25 to 1.5 in.) and offers numerous application options. For example, it is ideal for measuring flow and return temperatures on heating systems and can also be used for detecting superheating/subcooling on refrigeration systems. The fixed cable is used to connect the clamp probe to a measuring instrument (sold separately). The clamp probe is equipped with a high-quality NTC sensor and features a high measuring accuracy of up to ±1.8 °F (-4 to 185 °F).