The rapid temperature change test box is different from the national standard high and low temperature test box, and the national standard high and low temperature test box has no index of the cooling rate. The time from the ambient temperature cooling to the nominal minimum temperature is generally 90 to 120 minutes. High and low temperature alternating test chambers, high and low temperature hot and humid test chambers all have the requirements of variable temperature speed. The temperature change rate is generally required to be 1°C/min, and the speed can be adjusted within the range of this rate. The rapid temperature change test chamber cooling rate of heating or cooling faster, generally can reach 3 °C / min ~ 15 °C / min, in some temperature zones, temperature, cooling rate can even reach 30 °C / min or more. The temperature range of various specifications and speeds are generally the same, ie, -60 to +130°C, but the range of temperature variation for checking the cooling rate is not the same. According to the different test requirements of the test, the temperature change range of the rapid temperature change test chamber is -55 to +80°C, and some -40 to +80°C. There are two ways to describe the temperature change rate. One is the average heating and cooling rate in the whole course, and the other is the linear temperature rising and cooling speed (actually, the average speed is every 5 minutes). The overall average speed refers to the ratio of the difference between the maximum temperature and the minimum temperature to the time within the variable temperature range of the test box. At present, the technical parameters of the temperature change rate provided by foreign environmental test equipment manufacturers all refer to the average rate of the whole process. The linear temperature rise/fall rate refers to the temperature change rate that can be guaranteed for every 5 min period. In fact, for the rapid temperature change test box, the most difficult and most critical step to ensure the linear temperature rise and fall is the cooling rate that the test box can achieve during the last 5 min of the cooling section. From a certain point of view, the linear temperature rise and lower speed (average speed every 5 minutes) is more scientific. Therefore, the test equipment is best to have the two parameters of the average lift temperature rate and the linear lift temperature rate (average speed every 5 minutes). In general, the rapid temperature change test box linear temperature rise and fall speed (average speed every 5 minutes) is 1/2 of the average speed of the whole process. Pump Solenoid Valve,Hydraulic Pump Solenoid Valve,Vacuum Pump Solenoid Valve,Water Pump Solenoid Valve Shandong Iparts Trading Co., Ltd , https://www.cniparts.com