Sweating Guarded Hotplate Used for measuring heat and water vapor resistance under steady-state conditions.By measuring the heat resistance and water vapor resistance of textile materials, the tester provides direct data for characterizing the physical comfort of textiles, which involves a complex combination of heat and mass transfer.The heating plate is designed to simulate heat and mass transfer processes occurring near human skin and measure transport performance under steady-state conditions including temperature relative humidity, air velocity, and liquid or gas phases.
Working principle:
The sample is covered on the electric heating test plate, and the heat protection ring (protection plate) around and at the bottom of the test plate can keep the same constant temperature, so that the heat of the electric heating test plate can only be lost through the sample;The humidified air can flow parallel to the upper surface of the sample.After the test condition reaches the steady state, the thermal resistance of the sample is calculated by measuring the heat flux of the sample.
For the determination of moisture resistance, it is necessary to cover the porous but impermeable film on the electric heating test plate. After evaporation, the water entering the electric heating plate passes through the film in the form of water vapor, so no liquid water contacts the sample.After the sample is placed on the film, the heat flux required to keep the test plate constant temperature at a certain moisture evaporation rate is determined, and the sample wet resistance is calculated together with the water vapor pressure passing through the sample.
Post time: Jun-09-2022