The cold air in the working chamber can convent if the exhaust valve on top of the oven is open, the temperature is controlled constant automatically by digital display instrument.
开启箱顶排气阀可使工作室温之冷空气得以对流交换，温度控制采用数字显示仪表自动恒温调节。
2
The principle and approach ofconstant magnetic measurement for diameter of coiled tubing is introduced, and an instrument for the measurement is designed.
介绍了连续油管直径恒磁测量原理及方法，给出了测量装置的构成和实验数据，分析了其测量精度。
3
The phases of samples were analyzed by X-ray diffraction and their thermoelectric properties were tested by electric constantinstrument and laser thermal conductance instrument.