Environmental Test Equipment , Constant Temperature And Humidity Test Chamber

Constant temperature and humidity test chamber is also called constant temperature and humidity tester, constant temperature and humidity test chamber, programmable wet and heat alternating test chamber, constant temperature machine or constant temperature and humidity chamber. It is used to test the performance of materials in various environments and test equipment. The material is resistant to heat, cold, dry and moisture. For electronic, electrical appliances, mobile phones, communications, meters, vehicles, plastic products, metals, food, chemicals, building materials, medical, aerospace and other products used for testing quality.

FUNCTIONS

The constant temperature and humidity test chamber consists of thermostat (warming, cooling) and humidification. Through the rotating fan mounted on the top of the box, the air is discharged into the box to realize gas circulation, and the temperature and humidity inside the box are balanced. The data collected by the built-in temperature and humidity sensor of the box is transmitted to the temperature and humidity controller (micro The information processor) performs an edit process and issues a thermostat/humidity command through the air heating unit, the condenser, and the heating evaporation unit in the water tank.
Constant temperature and humidity box temperature adjustment is through the box built-in temperature sensor, collect data, adjusted by the temperature controller (micro information processor), turn on the air heating unit to increase the temperature or adjust the cooling solenoid valve to reduce the temperature in the box, Meet the temperature required for control. The humidity control of the constant temperature and humidity box is through a built-in humidity sensor, collects data, is regulated by a humidity controller (micro information processor), and is connected to a water tank heating element to increase the humidity in the tank or adjust refrigeration by evaporating the water in the water tank. Solenoid valve to achieve dehumidification in order to achieve the control of the required humidity.
The constant temperature and humidity box is provided with multiple protection measures; the temperature system is equipped with an over-temperature protection device under the condition that the maximum allowable safety temperature can be set, and the air heating element can be automatically shut down when the rotation fan stops; the humidification system can follow the humidification tank water level. The power supply is reduced and the power supply is stopped; the refrigeration system also stops working as the temperature of the cabinet increases (more than 40°C) or the humidity increases.

OPERATING PRINCIPLES

Through three interconnected systems: refrigerant circulation system, air circulation system, electrical automatic control system.
1. the constant temperature and humidity test chamber The refrigerant circulation system: The liquid refrigerant in the evaporator absorbs the heat of the air (the air is cooled and dehumidified) and begins to evaporate, resulting in a certain temperature difference between the final refrigerant and the air. Liquid refrigerant It also completely evaporates into a gaseous state, which is then inhaled and compressed by the compressor (pressure and temperature increase). The gaseous refrigerant absorbs heat through the condenser (air-cooled/water-cooled) and condenses into a liquid. After throttling through the expansion valve (or capillary tube), the refrigerant turns into a low-temperature and low-pressure refrigerant and enters the evaporator to complete the refrigerant circulation process.
2. the constant temperature and humidity chamber air ring system: the fan is responsible for the air from the air inlet, air through the evaporator (cooling, dehumidification), humidifier, electric heater (heating) after the air outlet to the user needs space The air sent out is mixed with the air in the space and returned to the return air.
3. constant temperature and humidity test box electrical automatic control system:
Including power supply and automatic control.
The power supply part through the contactor, the compressor, fan, electric add device, humidifier, etc. supply automatic control of the power is divided into temperature and humidity control and fault protection part: temperature and humidity control is through the temperature and humidity controller, Compare the temperature and humidity of the return air with the temperature and humidity set by the user, automatically run the compressor (cooling, dehumidification), humidifier, electric heating (heating) and other components to achieve automatic control of constant temperature and humidity.

INSTALLATION

In order to facilitate heat dissipation and maintenance of the cabinet, the place where this equipment is installed must meet the following conditions:
1, 300mm from the adjacent wall or utensils
2. In order to stabilize the function and performance of the test chamber, a place with a constant temperature of 15~35°C and a relative humidity of more than 85% should be selected.
3, the installation site environment temperature should not be drastic changes.
4, should be installed in the level of the surface (installation level instrument to confirm the level on the ground).
5, should be installed in places without direct sunlight.
6, should be installed in a well-ventilated place.
7, should be installed away from combustibles, explosives and high temperature heat source.
8, should be installed in dusty places.
9. Install it as close to the power supply as possible.