Patent ID: 7441439

Claim:
An apparatus for calibrating and testing a pressure switch, the apparatus comprising: a. a housing including an inside and an external surface; b. an air compressor located on the inside of the housing, the air compressor including a vacuum-side inlet and a pressure-side outlet; c. a first vacuum nozzle located within the external surface of the housing, the first vacuum nozzle being in fluid communication with the vacuum-side inlet of the air compressor; d. a second vacuum nozzle located within the external surface of the housing, the second vacuum nozzle being in fluid communication with the vacuum-side inlet of the air compressor; e. an internal positive pressure opening in fluid communication with the pressure-side outlet of the air compressor, wherein the internal positive pressure opening is located inside the housing of the apparatus; f. a recirculation circuit located on the inside of the housing, the recirculation circuit being in fluid communication with the vacuum-side inlet, the pressure-side outlet, the first and second vacuum nozzles and the internal positive pressure opening; g. a bypass control valve comprising a needle valve located within the recirculation circuit and a control knob located within the external surface of the housing, wherein the bypass control valve is capable of fine regulation of airflow for controlling the amount of air passing from the pressure-side outlet to the vacuum-side inlet of the air compressor; h. a conductivity indicator comprising two lead inputs located on the inside of the housing and an indicator light located within the external surface of the housing, the conductivity indicator operable to visually indicate whether the pressure switch is open or closed; i. a battery in electrical communication with the air compressor and the conductivity indicator, the battery located on the inside of the housing and adapted to supply power to the air compressor; and j. an electrical switch located within the external surface of the housing and configured as an on/off button adapted to permit electrical communication between the battery and the air compressor.