1 the limit vacuum measurement is carried out under the cold condition of the air furnace, and the vacuum system is tested by itself.
2 the time of the vacuum furnace is measured in order to start the vacuum pump and the vacuum degree of the vacuum is reached. In the test, the pre heating time of oil diffusion pump and oil booster pump is not included in the empty boiler.
3 the rate of pressure rise measurement in the vacuum furnace after full degassing in later half closed measurement, when the furnace reaches the limit vacuum degree, close the courage of the vacuum system shut down valves, vacuum pump, pressure rate of second readings when vacuum furnace of value vacuum furnace of minus the first reading, then divided by the time of the two reading notes, generally not less than 1h.
The first reading in general should be closed after the vacuum valve 15min;
4 work vacuum measurement in the vacuum furnace operation process, in the specified operating temperature of the test, should be able to achieve the required vacuum degree value.
5 the temperature rise time of the empty furnace is measured at room temperature and the vacuum in the furnace can be carried out after the vacuum has been reached. During the test, the input power of the furnace is equal to the rated power (allowable + 10% error), and the time from the power supply to the test temperature, that is, the heating time of the air furnace.
6 thermal stability of furnace temperature uniformity measurement in the vacuum furnace at the working temperature, measure the vacuum degree in vacuum. The arithmetic mean value of the maximum temperature difference of 5 times was measured 5 times. The measurement area is measurement points and the location, should be in accordance with the provisions of technical documents.