APR Series Split-Core Sensors

LEM split-core current sensors provide flexible and precise AC current measurement across a wide adjustable range

Image of LEM USA APR Series Split-Core SensorsLEM APR series split-core current sensors provide flexible and precise AC current measurement across a wide adjustable range from 10 A to 400 A, making them well suited for dynamic installation environments. Available in true RMS versions, they offer selectable output formats—including 4 mA to 20 mA, 0 V to 5 V, and 0 V to 10 V—to match diverse monitoring and control system requirements, all supported by a broad 30 Hz to 6,000 Hz bandwidth and an 18 mm aperture. The series also includes two electronic variants: the B10, designed for voltage output configurations, and the B420L, tailored for current output applications. Built on LEM PRiME (Planar Rogowski I Measurement) air core technology, APR sensors deliver reliable, accurate performance for energy and automation applications where dependable current measurement is critical.

Features
  • True RMS output
  • Split-core type
  • 0 VDC to 5 VDC and 0 VDC to 10 VDC switch selectable voltage output (APR-B10) or Loop powered 4 mA to 20 mA current output (APR-B420L)
  • DIN rail or panel mounting
  • Switch selectable measuring ranges
  • Insulating plastic case recognized according to UL 94 V-0
  • Equipped to measure VFD and SCR waveforms in current
  • Large aperture for cable up to 18 mm
  • High insulation between primary and secondary circuits
  • Eliminates insertion loss
  • Easy installation
Applications
  • VFD controlled loads
  • SCR controlled loads
  • Switching power supplies and electronic ballasts
Published: 2026-02-17