Principle and method steps of walk-in constant temperature and humidity test chamber

Ⅰ. The principle of walk-in constant temperature and humidity test box

The chamber body of the walk-in constant temperature and humidity test box (the main body of the test chamber) is divided into six chambers and a double-opening chamber door, the size is 1800x 2000 mm, and the chamber body is made of high-quality stainless steel plate for the inner liner (to prevent prolonged exposure to The inner wall is rusted under the humidity running state), the outer liner is made of high-quality color steel plate, the thermal insulation medium is polyurethane rigid foam insulation, light weight and anti-impact, good heat insulation performance, the door material is also made of color steel plate, and the door handle is inside and outside Open type, so that the test personnel can freely open the door from the closed room.

Ⅱ. The tools of the walk-in constant temperature and humidity test box

The chamber body base of the walk-in constant temperature and humidity test chamber adopts 8# channel steel welded mesh frame, so that it can bear the weight of the chamber body and personnel specimens under horizontal conditions, without causing unevenness and cracking on the bottom surface of the chamber body. . Bearing capacity 200kg/per square meter.

The heater of the walk-in constant temperature and humidity test chamber adopts a porcelain-frame nickel-chromium wire electric heater, which has small thermal inertia and long service life. The controllable pulse duty cycle PID signal is output by the instrument, and it is controlled by the solid state relay, and the control is stable and reliable.

Ⅲ. How to use the walk-in constant temperature and humidity test box

1. Turn on the heating switch, all three stages are turned on at the beginning, and the heating speed is fast. After heating to the required temperature, if the required test temperature value is below 100 °C, the second stage heating switch can be turned off, leaving only one stage. The heating switch can be turned on for temperature compensation. If the required test temperature is above 100°C, the second to third stage heating switches can be reserved for temperature compensation.

2. Photochemical reactions are usually not very sensitive to temperature, but the rate of any subsequent reactions depends on the temperature. The rate of these reactions increases with the increase of temperature. Therefore, it is very important to control the temperature during UV exposure. , the temperature of the constant temperature and humidity test chamber must be consistent with the maximum temperature of the material directly exposed to sunlight. In this instrument, the ultraviolet exposure temperature can be set at any temperature between 50 ° C and 80 ° C according to the illuminance and ambient temperature. One kind of temperature: The UV exposure temperature is adjusted by a sensitive thermostat and blowing system to make the temperature of the aging box have excellent uniformity.

3. A unique condensation device is used to simulate the effect of rain and dew on the surface of the sample. During the condensation cycle, the water injection tank at the lower part of the test inner shell is heated to generate steam heat, and the steam maintains the 100% relative humidity in the constant temperature and humidity test chamber. With a certain temperature rise, the sample constitutes the cooling effect of the ambient air on the inner side wall of the test box, so that the temperature of the test surface is lower than that of the steam. This temperature difference can make liquid water continuously condense on the test surface during the entire condensation cycle.