The Testo 552 Digital Vacuum & Micron Gauge (0560 5522 01) is ideal for monitoring the evacuation of air conditioning, refrigeration, and heat pump systems. It is rich in features that make your work faster, easier, and more accurate. Precise deep vacuum measurements measured at single digit resolutions are carried out with Pirani sensors. The Testo 552 provides real-time calculations for the saturation temperature of water, which determines the proper micron / temperature levels at which moisture is removed from the system. These internal calculations inform you when the pressure is low enough to meet your evacuation target. This saves you time, and assures that the system is now free from moisture and contaminants. User defined alarm points alert you when target values are reached. The new and improved Testo 552 with Bluetooth links to your smartphone or device, and to the free testo Smart Probes app.