What is a micron gauge and why is it important?
Anytime the air conditioner’s copper lines that carry refrigerant are opened air and humidity enter. Even the tiniest amount of water vapor left in the system will cause acid to form which will eat away at your compressor. A vacuum pump is used to remove water vapor and other contaminants. However, to ensure that all the water vapor is removed the level of vacuum must be less than .07% of atmospheric pressure. A refrigerant gauge would have to have over 1,500 hash marks in the space of less than an inch for it to measure such a pressure. It’s not possible. Micron gauges are designed precisely for that purpose. Many if not most HVAC companies don’t use micron gauges. Many don’t even own one because most customers know nothing about them and because the adverse affects from not using one can take years to manifest (if they manifest at all). See the pictures.
