Testo 557 Digital Vacuum Gauge fulfills numerous functions, which are required for working on refrigeration systems and heat pumps in just one instrument. The testo 557 digital manifold has a 4-way valve block, a large backlit display, and sight glass. Two NTC thermistor clamp probes provide superior accuracy for simultaneous, real-time superheat and subcooling readings.

Application: superheating/subcooling calculation, vacuum measurement, temperature-compensated leakage test.