Abstract: An apparatus for calibration and testing of pressure switches which are typically used in residential and commercial HVAC systems. The apparatus can be used to test, set or adjust a pressure switch to the manufacturer's specifications. The apparatus includes an exterior housing with an on/off switch, two vacuum nozzles, and a bypass control valve mounted thereon, with the inside of the housing including an air compressor in communication with the nozzles and the bypass control valve. The air compressor typically operates from a battery power supply located within the housing. A pressure measuring device, such as a differential pressure gage, and a conductivity indicator are typically used in conjunction with the device to calibrate adjustable pressure switches and to test and diagnose faulty pressure switches.

Abstract: An apparatus for calibration and testing of pressure switches which are typically used in residential and commercial HVAC systems. The apparatus can be used to test, set or adjust a pressure switch to the manufacturer's specifications. The apparatus includes an exterior housing with an on/off switch, a vacuum nozzle, a pressure nozzle, and a bypass control valve mounted thereon, with the inside of the housing including an air compressor in communication with the nozzles and the bypass control valve. The air compressor typically operates from a battery power supply located within the housing. A pressure measuring device, such as a differential pressure gage, and a conductivity meter are typically used in conjunction with the device to calibrate adjustable pressure switches and to test and diagnose faulty pressure switches.