Field Strength Meter


The FSM Magnetic Field Strength Meter from Ampetronic is a cost effective and simple solution for measuring, setting up and commissioning an induction loop system to the requirements of IEC60118-4. The meter is an ergonomically designed hand held instrument for measuring loop system performance. There are three calibrated operational modes for the assessment of Background Noise, Field Strength and Frequency Response as required to ensure correct function of the loop system. The meter also doubles as a loop listener, with a headphone output to listen to the signal in the loop.

The meter is supplied in a soft case  and with  full operating instructions including a guide to commissioning. The Ampetronic FSM can be used to monitor, set up or commission any induction loop system regardless of the manufacturer or type.

This product is available through authorized resellers.

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  • Accurate set-up and commissioning
  • System monitoring and maintenance
  • Site surveys
  • Certification to IEC60118-4
  • Assessment of frequency losses due to metal
  • Assessment of loop coverage and overspill
  • Assessment of background noise

Included Accessories

  • Soft carry pouch
  • User guide/handbook
  • Commissioning Certificate (template)
  • Batteries


  • Simple assessment of any system to
  • Three modes of operation for three test types
  • A-Weighted background noise • Broad band mode (50Hz – 8kHz)
  • Frequency response (100Hz, 1kHz, 5kHz)
  • True RMS detection calibrated to
    400mA/m = 0dB
  • Wide viewing angle LED display
  • Colour coded LEDs for simple readout
  • Resolution to 1dB
  • Head phone output with volume control
  • Ergonomic, rugged, light weight construction
  • Quick start guide
  • Soft carry case
  • 5 year warranty

Also Needed



Frequency Response50 Hz to 8 kHz ±0.25 dB, 30 Hz to 10 kHz -3 dB
Gain StabilityBetter then 0.5 dB over all conditions


LEDsColor Coded - Green for -3 to +3 dB, Red for -4 to -22 dB


Headphone Connector3.5 mm Stereo Connector, 16 Ohms (32 Ohms per side)


Coil OrientationVertical when held upright
Reference Level400 mA/m (In field strength mode)


Battery TypeTwo (2) x AA Alkaline
Battery LifeUp to 100 hrs. use, dependant on use pattern
Battery MonitorBattery OK when LED illuminated


Width3.3 in. (84 mm)
Height5.5 in. (140 mm)
Depth1.0 in. (27 mm)
Shipping Weight1.2 lbs. (0.54 kg)
Weight1.2 lbs. (0.54 kg)


Relative HumidityIP20 Protection, 20 to 90% Relative Humidity, 14 F (-10 C) to 113 F (45 C)