FSM Field Strength Meter


The FSM 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 full operating instructions including a guide to commissioning.

Williams AV is proud to offer Ampetronic Loop products in the United States and Canada. To purchase Ampetronic loop products in other countries, please visit https://www.ampetronic.com/


Magnetic field response Coil orientation: Vertical when unit held upright
Reference level: 400mA/m (In Field strength mode)
Frequency response
50Hz to 8kHz ±0.25dB
30Hz to 10kHz -3dB
Gain stability: Better than 0.5dB over all conditions
Outputs Display:
Flying spot LED bar graph with wide viewing angle
Colour coded (green for -3dB to +3dB)
Audio (headphone):
16Ω min (32Ω per side)
3.5mm stereo jack connector
Power Battery: 2 x AA alkaline (supplied)
Battery monitor: Battery OK when LED illuminated
Battery life: Up to 100hrs use, dependent on use pattern
Physical Dimension: 84 x 27 x 140mm (meter only)
Weight: 150g excluding batteries
Operating environment:
-10 to +45˚C
10 to 85% RH


5 Years

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