Quick Car 0-20 psi Liquid Filled Air Pressure Gauge -56-021
All liquid filled gauges are affected by temperature and atmospheric changes. The air and liquid inside the gauge expands and contracts with these changes. An internal pressure build up will affect your reading. The internal gauge pressure must be the same as the environment to get a true reading. This is why all liquid filled gauges are equipped with bleeder valves to equalize the internal pressure to that of the environment. QuickCar has taken a new approach to this issue and made a more user friendly tool. QuickCar has designed an interior diaphragm that automatically adjusts to these changes. As a result no manual equalization is necessary.