Vacuum pump gauge analogue ASHRAE recommends evacuation to below 1000 microns for moisture removal and below 500 microns after replacing a compressor. Some equipment manufacturers call for evacuation to 400 microns to ensure that harmful water vapor is removed from the system. Micron gauge HVAC/Refrigeration: To pull a deep vacuum, removing moisture (which boils off below 500 microns) for proper system charging and function. Automotive: Diagnosing engine performance by checking intake manifold vacuum; also used for A/C service. Vacuum SKU: vpg Categories: Manifold and Accessories, Tools and Multi Meters
