On the working spot of centrifugal water pump, the detection can be carried out only by fixing the negative pressure translator in the original position of vacuum meter.
在离心式水泵工作现场只须把原安装真空表的位置换上负压变送器即可进行检测。
Methods The vacuum negative pressure meter and the delayed control line were used.
方法：用真空负压表、延迟控制线路，接通电话机免提键、存储拨号键。
First close the plug of a vacuum or pressure meter, if so mounted on the pump, connected to the pump before starting the motor and then open it when the motor move in the normal speed;
如果泵上装有真空表或压力表，要关闭其与泵相连接的旋塞再启动电动机，待转速正常后再打开；
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