What is Absolute pressure 0.5 kg
Because of the low temperature in the high air and the high speed of the aircraft, kilogram pressure (sometimes abbreviated to kilogram) is actually referred to as "kilogram force per square centimeter" (the symbol KGF /cm2), which means a force of one kilogram per square centimeter.
1 kg pressure = 1 KGF /cm2 = 9.8 N/cm2 = 98000N/m2 = 98000 Pa
1 standard atmosphere = 10,000 Pa= 1.02 kg pressure.
The difference between absolute pressure and gauge presssure is that absolute pressure refers to the actual pressure, while gauge pressure refers to the pressure relative to atmospheric pressure. For example, 2 kg of gauge pressure means 2 kg higher than atmospheric pressure, which means the actual pressure is 1.02 + 2 = 3.02 kg.
Similar to kilogram pressure, PSI is often used in British units to refer to pressure.
1 PSI = 1 lb/in2 = 0.4536 KGF /in2= 6893 Pa
Similarly, PSI differs between absolute pressure (PSIA) and surface pressure (PSIG). A standard atmospheric pressure is about 14.7PSIA, and 14.7 PSIG means 14.7PSI higher than atmospheric pressure, equivalent to 29.4 PSIA.