Portable hygrometer is a portable and rugged dew point monitor. It is normally used for moisture measurements from -100 to +20 °C dew points. The uses of this hygrometer include spot-checking of the dew point of flammable and nonflammable process gas such as natural gas, nitrogen, compressed air, and hydrogen. The operation is very simple, just connect the sample gas to the inlet port compression fitting, turn on the power and within seconds it is ready to display the dew point of the sample gas.