Because different users of various kinds of drying objects are not the same blackness, as a factory to try to use a common form of radiation heat metering method to cover up, not only technically have a certain degree of difficulty, and, above all, the use of the face is too narrow. Thus, to the user can withstand the quotation as the starting point, the General Electric vacuum drying box are selected to first heating the vacuum chamber wall, and then the wall-oriented workpiece radiation heating method. In this way, the temperature sensor on the surface of the control temperature can be placed in the vacuum outside wall. Sensors can withstand convection, conduction, and radiant heat together. The glass bar thermometer in the vacuum chamber can only withstand radiant heat, but also because the glass rod blackness can not reach 1, the appropriate part of the radiation heat is refracted, so that the temperature of the glass bar thermometer reflects must be lower than the external temperature readings. Generally speaking, 200 ℃ working conditions when the external temperature reading and glass bar thermometer reading between the two 30 ℃ is normal.
