To calculate absolute pressure when a barometer reading is given, simply add the barometer reading to the atmospheric pressure at sea level, which is approximately 101.3 kPa or 14.7 psi. This will give you the absolute pressure at the specific location where the barometer reading was taken.
Low pressure
Gives a reading of what the pressure in the system is.
Arterial pressure
To check the refrigerant level in your AC system, you will need a pressure gauge. Attach the gauge to the service valve on the AC unit and compare the reading to the manufacturer's recommended pressure levels. If the pressure is too low, it may indicate a refrigerant leak. If you are unsure how to do this, it is best to contact a professional HVAC technician for assistance.
gauge pressure
air pressure
Second
I'm not a mechanic / technician but I've heard of a plugged PCV system ( valve, hoses etc ) blowing the oil dipstick up off its seat - but I don't know if that raises the oil pressure reading on the gauge ? ( of course , there is a normal change in oil pressure from idle as the RPM's go up - to a point )
Air pressure
NO it will not.
149 psi