（1）判断感应电。用一般试电笔测量较长的三相线路时，可在试电笔的氖管上并接一只1500pF的小电容（耐压应取大于250V），在测带电线路时．电笔可照常发光；如果测得的是感应电，试电笔不亮或微亮，据此可夫断出所测得的是电源还是感应电。（2）判别交流电源同相或异相。两只 (1) to determine the induction. With a general test pencil to measure a longer three-phase line, the test can be connected to a Neon tube and 1500pF a small capacitor (pressure should be greater than 250V), while measuring live lines. The pen can shine as usual. If the measured voltage is sensed, the test pen does not light up or is slightly bright, so that the power supply can detect the power or inductive power. (2) Discrimination AC power in-phase or out-of-phase. Two