Principle of Environment Chamber

Environmental Chamber is humidity and temperature controlled chamber to provide constant temperature and humidity.

Gester Instruments provides temperature and humidity chamber temperature ranges from -60℃ to 150℃ (can be customized). small environmental chamber 80L available; 80L-1000L available. Here for more information about Temperature and Humidity Cabinet.

Mainly the constant temperature and humidity chamber is used as following:

– to condition samples before some test for preparation;

– to provide the required test environment for some test, for example, cold ross flex test – to flex sample in low temperature;

– to test sample change under certain temp and humidity condition as a independent test

Environment Chamber Working Principle

Environmental chamber is mainly composed of temperature system(refrigeration & heating), humidity system, air circulation system, and sensor systems.

-Temperature System

Heating system: The heating system of the temp and humidity controlled cabinet is relatively simple compared to the refrigeration system. It is mainly composed of high-power resistance wire. Because the temp and humidity controlled cabinet requires a fast heating rate, the heating system power of the test box is relatively large. The temperature inside the climatic test chamber is filled by the air circulation to fill the inside of the test chamber with the high temperature generated by the resistance wire. The temperature and the balance inside the test chamber are controlled by the sensor and the control system.

Refrigeration system: this is a important part of temperature humidity test chamber. Normally, The cooling mode of the test chamber is mechanical refrigeration and auxiliary liquid nitrogen refrigeration. Mechanical refrigeration uses compression refrigeration which consists of Compressor, condenser, throttling mechanism and evaporator. Refrigeration system is divided into single-stage refrigeration and cascade refrigeration.

-Humidity system: The humidification method of the climate chamber is steam humidification method, that is, the heated water vapor is directly injected into the test chamber to humidify, and the humidification speed is fast and the humidification control is sensitive. The dehumidification mode of the test box is mechanical refrigeration dehumidification, cooling the air to zero temperature, so that no more than one water vapor in the test chamber is condensed, thus reducing the humidity. This dehumidification process needs to be combined with temperature system, refrigeration system, control system, etc.

-Control system: The control system is the core of the walk in climate chamber, which determines the important parameters such as the heating rate and accuracy of the test chamber. The controller of the constant climate chamber adopts PID control, and some control modes using combination of PID and module.

-Air circulation system: The air circulation system consists of a motor with a centrifugal fan that provides circulation of air in the environmental chamber.

-Sensor system: The sensor is mainly a temperature and humidity sensor. The temperature sensor is a platinum (Pt) thermal resistance measurement, and the humidity measurement method is a dry and wet thermometer method.