The 14777 is simple to use just connect the thermistor lead to an access port on the system or off the inlet tee on the vacuum pump.
Press the on/off button, then start the vacuum pump.
For large systems, you can save battery life by running the pump for a few minutes, then turning the vacuum gauge on all it takes is the push of a button.
No. 14777 Compact electronic vacuum gauge.
Specifications Power Supply .One 9V battery (included) Vacuum Fitting 1/4IN MFL Length of Lead 6 feet (8.3 m) Vacuum Rating 29 in./Hg Dimensions 3IN H x 2.5IN W x 1IN D (7.62 cm x 6.35 cm x 2.54 cm)