spark-gap voltmeter

例句：

1. 1.The spark-gap voltmeter was used to measure the voltage across the circuit.
   火花间隙电压表用于测量电路两端的电压。
2. 2.The engineer used the spark-gap voltmeter to troubleshoot the issue with the power supply.
   工程师使用火花间隙电压表来诊断电源供应的问题。
3. 3. The technician carefully read the readings from the spark-gap voltmeter to ensure accuracy.
   技术员仔细读取火花间隙电压表的读数，以确保准确性。