R22 (Chlorodifluoromethane) is a chemical that has been used for years in a variety of air-conditioning and refrigeration applications and within a variety of markets. It also has been used in construction work, the food-processing industry and in supermarkets as a coolant for refrigeration, to assist in maintaining a certain pressure and temperature.
R22 refrigeration gauges measure the amount of R22 in the coolant line. Because R22 is a gas and not a liquid, the refrigeration gauge reads in pounds per square inch. The measurement is made by connecting the hoses to the coolant line and releasing the valve. A user can measure the amount of R22 from the refrigeration gauge within the air-conditioning system, and from the gauge's temperature.
R22 is an abbreviation for chlorodifluoromethane, which is a hydrochlorofluorocarbon--a class of gasses that have been identified for their effects on the Earth's ozone layer. Chloroflurocarbon gases have been blamed for years now for eroding the planet's protective layer.
R22 is primarily used in air-conditioning systems. These units are shipped, transported and equipped with R22 refrigeration. A machine typically uses the same supply of R22 throughout its lifespan. It is not unusual, however, for R22 to deplete within a system or to leak from an air-conditioning system.
Each set of R22 refrigeration gauges has a gauge for the high-side pressure and low-side pressure. Some automobile gauges only have a low-side gauge. You can determine if the system is working correctly by comparing the high- and low-side readings. For the R22 refrigeration gauge to be useful, it must not only maintain a particular pressure, but also a precise temperature, because refrigeration gas like R22 should never fall below freezing. Lines that are functioning properly at a high pressure (220 psi) should run in the neighborhood of 110 degrees. The coolant is measured as it streams away from the condenser. So the higher the pressure, the hotter the gas will be; and the lower the pressure, the lower the temperature will be.
The R22 refrigeration gauge is important because it helps maintain a certain pressure and temperature for your refrigerator. If the refrigerator were to run low on refrigerant, the refrigerator would freeze up due to a lack of pressure.