真有效值电量传感器是针对平均值测量法不能准确测出其有效值而设计的。有效值又称均方根值（rms）。利用此原理开发的WB 系列真有效值电量隔离传感器有两大类： 一类是单路交流电流、电压及交直流通用输入， 模拟量输出的真有效值转换电量隔离传感器； 另一类为多参量组合型的智能变送器， 其输入单相或三相交流电压、电流， 输出有电压、电流、有功、无功、功率因数、频率等， 数据接口为RS- 485 总线。文中给出了交/ 直流电流/ 电压型WB 系列真有效值电量隔离传感器的原理框图及其直流电压输出型、直流电流输出型和频率输出型的应用示例。关 键 词 ： 电量隔离传感器； 真有效值； 平均值； 原理； 应用Abstract: TRMS electricity isolated sensor is designed for test that can not be tested exactly by average test method, RMS is also root mean square. By this principle, we develop the WB TRMS electricity isolated sensor, The sensor divide into two classes, one is single AC current, voltage and AC/ DC input with analogue output, other is multi- parameter intelliget transmitter, It has single -phase or three-phase AC voltage、 current input, it can output voltage, current, effective power, not-effective power, power factor, frequencyand etc, the interface is RS- 485 bus, In this writings, we give the principle scheme of AC/ DC current、voltage WB TRMS electricity isolated sensor and application example of DC voltage DC current and frequency output.Key Words: Electricity isolated sensor, TRMS, Average, Principle, Application