HO-NP Series. LEM HO-NP series multi-range current transducers for the electronic measurement of current. The HO-NP series can measure dc, ac and pulsed current with galvanic separation between the primary and the secondary circuit. Features and Benefits. Open loop multi-range current transducer. Voltage output. Low power consumption. Fixed offset and sensitivity. Small size and space saving. High immunity to external interference. Suitable for industrial applications. Factory calibrated