A power meter, or energy meter, is a measurement device, which is able to measure the voltage and the current of an electrical consumer, for example a compressor. By measuring these values, the power meter is able to calculate the power consumption of the consumer. Typically, it outputs the Current, Voltage, Frequency, Active and reactive power, active and reactive energy, power factors and more.

Compressed air is an expensive energy form, since it's produced by compressors, which have a low efficiency factor. Designing a compressed air system is mostly done by summing up all machines on the demand side and adding some safety volume to that. But that means at the same time, the bigger compressor will then use more electrical energy.

In many installations, measurement providers are measuring only the voltage and current on a single phase. By then assuming power factors, without knowing the actual phase shift, the measurement providers then specify the electrical power consumed by compressors. But this can not be considered as a real power measurement, as assumed factors are taken into place, which is not what operators want to have.

A brand-new compressor will have a defined electrical energy consumption at a certain air flow output. But as a compressor is a machine which wears off, it is likely that at a certain age the compressor will deliver less air flow at the same rate of energy consumption. This means, the electrical costs are the same or even higher, but the air flow output gets less.

SUTO current sensors are Rogowski current coils. The advantage is, that the Rogowski coils are easily installed by simply clamping them around the cables or wires. This is possible without interrupting the process. The wire will then induce a current into the coil, which is then transformed to an electrical signal.