Large current and frequency range that can be measured by Rogowski coil

Rogowski coil can measure the huge current and frequency range . The limit values given are for reference only , Sometimes a special system can be designed to operate beyond the limit .

ceiling ：

The direct output of the coil depends on the rate of change of the current . For sufficiently high current and frequency , The output can be large enough to cause voltage breakdown . The coil with low mutual inductance is most suitable for high current and high frequency .

Resonance limit ：

Each coil has a self resonant frequency , This is caused by its self inductance and turn to turn capacitance . Resonance also depends on other factors , For example, cable capacitance . The resonance can be controlled by an appropriate damping circuit , However, coils higher than their resonant frequency are usually not used . The limit is indicated by the vertical dotted line . About special high frequency coils , See separate pages .

Coil working amplitude diagram

Lower limit ：

At low current and low frequency , The direct output of the coil is very low , And the practicability of the current sensor is limited by noise . The rigid coil with large mutual inductance is most suitable for very low current measurement . The low current limit can be extended by using multiple primary turns around the coil , Or in the case of flexible coils , The low current limit can be extended by winding the coil around the conductor several times . Electronic method of signal recovery , Such as filter or phase sensitive detector , It's also very useful. .

The above is the large current and frequency range that can be measured by Rogowski coil