Compressed air dew point measurement requires a dew point meter for measurement; there are two common compressed air dew point measuring instruments. Their respective characteristics are as follows：

1. Mirror dew point meter

The principle of the dew point meter is to cool the measured gas to a certain temperature by means of refrigeration, and the water vapor in it can condense on the mirror surface, and then measure the temperature at the time of condensation according to optical principles.

In theory, this method can measure any dew point value as long as all refrigeration temperatures can be realized. But the limitation is that the gas to be measured must be pure enough without any impurities and pollution, otherwise it will cause measurement errors; in addition, due to the use of refrigeration, the working principle is relatively complicated, and each measurement takes a certain amount of time, so It is not suitable for on-site testing and is mostly used in laboratories.

2.Capacitance/Resistance dew point meter

This dew point instrument is characterized by small size, easy to carry, and large measurement range. Its sensor is usually an alumina sensor, which can measure the dew point at the lowest temperature of -100°C. The limitation of this type of instrument is that it can only measure the dew point temperature at atmospheric pressure. And in long-term use, the dew point sensor will have a negative offset, so it needs to be calibrated.

Different test methods are suitable for different application scenarios, and you can choose according to your actual needs.