Connect your desired tool to the air compressor.
Fill your air compressor tank to its maximum rated pressure.
Adjust the pressure regulator down to 0 psi while you are running the connected tool.
Adjust the pressure upward toward the tool's rated running pressure while the tool is still running. Read the air line pressure gauge to determine when the desired psi has been reached. This is the gauge closest to the connected tool.
Lock the regulator when the air line pressure gauge displays your desired pressure reading.