Measurement of heating time of electric heating pipe test method, data source: People's Republic of China machinery industry standard JB/T2379-2016 "Metal tubular electric heating element"
6.5 heating time measurement
6.5.1 During the test, the component is placed in still air, and the component is connected to the test voltage in a cold state to measure the time to reach the test temperature.
6.5.2 The test voltage is the voltage at which the component reaches 0.73 times the rated power. The test temperature is 90% of the operating temperature
6.5.3 Determination of test temperature: use a surface thermometer or thermocouple to measure the temperature at the temperature measurement point specified in the component shell, and take the average temperature measured at each temperature measurement point as the measurement temperature. The measuring points of the element within 1m of the heating length are located at 1/4, 1/2 and 3/4 of the heating length of the component, respectively. For components with a heating length greater than 1m, a temperature measurement point should be taken every 200mm.
6.5.4 For the components that can be estimated to meet the requirements of the heating time, the power supply voltage should be reduced for testing when measuring, and if it is qualified, it is considered to be qualified. Otherwise, the voltage should be increased after the component is completely cooled before the voltage is energized until the specified test voltage is known.
