电线电缆的绝缘电阻测量值必须换算成每千米的绝缘电阻值，与直流电阻所不同的是，绝缘电阻值与电线电缆的长度成反比；低压电线电缆的绝缘电阻检测时的测量电压有100V、250V、500V和1000V四种，其中100V和500V的检测电压在质检部门检测时使用比较广泛；所测电线电缆的长度无明确规定，但为了测量和计算方便，一般取10m进行测量。测量前的充电时间一般为1分钟。
The measured value of insulation resistance of wires and cables must be converted to the value of insulation resistance per kilometer. Unlike DC resistance, the value of insulation resistance is inversely proportional to the length of wires and cables. There are four kinds of measuring voltage for insulation resistance detection of low voltage wires and cables: 100V, 250V, 500V and 1000V, of which 100V and 500V are in quality. Inspection departments are widely used in detection; the length of the wires and cables measured is not specified clearly, but in order to measure and calculate conveniently, 10 m is generally taken for measurement. The charging time before measurement is usually 1 minute.