Temperature and humidity meter what methods to use?

In industrial and agricultural production, meteorology, environmental protection, national defense, scientific research, aerospace and other departments, often need to humidity measure and control to the environment. To the environment temperature and humidity control, and monitoring and analysis of industrial materials moisture value has become one of the common technical conditions, but in a regular environment parameter, humidity is the most difficult to accurately measure a parameter. This is because is much more complex than the measurement temperature measuring humidity, temperature is an independent is measured, and the humidity is affected by other factors, Atmospheric pressure, temperature) The influence of. In addition, the calibration of humidity is also a problem. Foreign production of humidity calibration are expensive, so what are temperature and humidity meter using method? Dynamic method (common humidity measurements are: Dual pressure method, dual temperature method, the shunt method) , a static method ( Saturated salt method, sulfuric acid method) , dew point method, wet and dry bulb and electronic sensor method. Here is a simple introduce two methods: (1) dual pressure method, dual temperature method is based on the thermodynamics of P, V, T balance principle, balance for a long time, shunt method is based on the absolute humidity and precise mixture of absolute dry air. The adoption of modern measurement and control means, these devices can be quite precise, but due to the equipment complex, expensive, operation time consuming work, mainly for the use of standard measurement, the measurement precision can reach & plusmn; More than 2% RH. (2) saturated salt method, the static method is the most common method of humidity measurement, simple and feasible. But the saturated salt law of liquid and gas two-phase equilibrium is strict, higher requirements on the stability of the environment temperature. Requirements to use for a long time to balance, low humidity point for longer. Especially in the indoor humidity and humidity difference is bigger, the bottle open all need to balance 6 ~ 8 hours at a time. (3) electronic humidity sensor and humidity measurement method of electronic type humidity sensor products belong to the rise of industry in the 90 s, in recent years, both at home and abroad have made progress in the field of research and development of humidity sensor. Moisture sensor is from simple moisture sensor to integration, intelligent, the direction of the rapid development of multi-parameter detection, for the development of a new generation of humidity measurement and control system has created favorable conditions, and to increase the humidity measurement technology to a new level.