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2023-06-01 0 Views

Measuring principle of the dew point meter

The dew point meter is suitable for industrial applications such as air drying equipment, plastic injection molding equipment, glove box drying equipment, lithium battery humidity detection, hydrogen, carbon dioxide, humidity detection, etc. pXYTextile Testing Instruments, Testing Equipment Manufacturer


The sensor chip is made of a special Material, the surface is covered with a Teflon layer, which can resist chemicals and pollutants for a long time, and the product also has an auto-calibration function. When the dew point is below -60℃ Td, the self-calibration function will automatically start to ensure the accuracy of the product. pXYTextile Testing Instruments, Testing Equipment Manufacturer


Principle of the dew point meterpXYTextile Testing Instruments, Testing Equipment Manufacturer


This is a classic measuring method. Flow the measured sample gas through a specific desiccant, the moisture contained therein is absorbed by the desiccant, weigh the moisture content absorbed by the desiccant and the ratio of the Psample gas volume to sample gas volume is the humidity of the sample gas. The advantage of this method is high precision and the maximum allowable error can reach 0.1%. grams), which is difficult especially for low humidity gases, and the sample gas flow needs to be increased, resulting in longer measurement time and errors (the measured humidity is not instantaneous). pXYTextile Testing Instruments, Testing Equipment Manufacturer


This method is therefore only suitable for measuring gases with a dew point above -32°C. It can be said that there are only a few devices on the market that measure moisture exclusively using this method. pXYTextile Testing Instruments, Testing Equipment Manufacturer


In everyday life we ​​can observe that when the air temperature drops at night, some of the moisture in the air is separated and dew or frost forms. pXYTextile Testing Instruments, Testing Equipment Manufacturer


This shows that with a constant water vapor content, due to the temperature drop, the water vapor that is not saturated in the air can become saturated vapor, the excess waterr however be precipitation. pXYTextile Testing Instruments, Testing Equipment Manufacturer


The temperature at which water vapor is saturated is called the “dew point”. After the dew point temperature has been measured, the water vapor content can be determined from the water vapor saturation content table. pXYTextile Testing Instruments, Testing Equipment Manufacturer


Since the water vapor content does not change as the temperature drops, the dew point measurement is actually the absolute humidity. A lower dew point means less moisture in the air. pXYTextile Testing Instruments, Testing Equipment Manufacturer


The dew point can be measured with a special dew point meter. For example, after passing through the dryer, the dew point of the air is -50°C and the saturated moisture content, which corresponds to -50°C, is 38.89 mg/m3, indicating that the air still contains this moisture. pXYTextile Testing Instruments, Testing Equipment Manufacturer


When the dew point is -60°C, the saturated moisture content is 10.68 mg/m3. The lower the dew point, the greater the drought. pXYTextile Testing Instruments, Testing Equipment Manufacturer

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