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This article is reproduced from: http://www.shqyyb.cn/Tec/159.html. Keywords of this article: Portable dew point meter. http://www.shqyyb.cn/ A portable dew point meter is an instrument that can directly measure the dew point temperature. It has high humidity measurement accuracy, but requires a mirror with high smoothness, a high-precision temperature control system, and a highly sensitive optical detection system for detecting dew drops. It cools a mirror in the moist air of the sample until dew drops appear on its surface; the average temperature of the mirror at that moment is then measured, and this value represents the dew point temperature. The temperature of the gas tested by a portable dew point meter is usually room temperature. Therefore, when the airflow passes through the dew point chamber, it affects the mass and heat transfer processes in the system. With other conditions held constant, increasing the flow rate facilitates mass transfer between the airflow and the mirror surface. For example, when performing low dew point measurements, the flow rate should be increased slightly to speed up the formation of the dew layer; however, the flow rate must not be too high, as this can cause overheating problems, which is particularly evident in Peltier-based dew point meters with relatively low cooling capacity. It is necessary to select an appropriate flow rate in dew point measurement, as changes in flow rate affect the thermal equilibrium of the system; too high a flow rate can lead to a decrease in the pressure inside the dew point chamber. Typically, the flow rate of the instrument ranges from 0.4 to 0.7 L·min-1, but the choice of flow rate should depend on the structure of the dew point chamber and the refrigeration method used. When in use, we can consider pre-cooling the gas to be tested before it enters the dew point chamber, which can reduce the impact of heat transfer. Shanghai Quanyun Instrument Co., Ltd. Contact phone: 021-57629782 Company fax: 021-57629781 Mobile number: 15801876667 Contact person: Bao QQ: 1609345838 Address: Room 519, No. 32 Xinxin Road, Cheden Town, Songjiang District, Shanghai