Test kit contents
• HLS-2D loop driver
• 12V DC power supply
• 2 x 4mm connector plugs for the loop cable
(cable not supplied)
• 3.5mm audio cable
1.
Separate indication for power, input signal and
loop current
2.
Loop output connectors using standard 4mm
banana plug test sockets
3.
12V DC power input, 2.1mm centre positive
4.
Audio input, 3.5mm stereo jack
Additional equipment required
• R1 Receiver with iOS Device and Loopworks app or FSM with test record sheet
• Signal source - mobile phone, MP3 player or signal generator, with Ampetronic test tones
• Loop cable - 25 to 30m (80-100ft) of 1.5mm
2
(AWG 16) single core wire fitted with supplied
connectors
• Tape measure
Test signals and record sheet template available from www.ampetronic.com/signals
Optional equipment
• True RMS multimeter to monitor output current
• Additional short link cable (2x4mm connectors) if multimeter is used
• 12 volt battery (a fully charged 12 volt 4800mAH battery will give approximately 8 hours of
testing time)
Document outline
Determining metal loss and background noise levels are important steps in designing a proper
hearing loop system that meets the IEC 60118-4 international standard.
This test procedure uses the HLS-2D loop driver which is mounted in a compact rugged case and
pre-set to simplify and reduce set-up and testing time.
The document will guide you through the metal loss and background noise testing process utilising
either the R1 Loopworks Measure Receiver, or the FSM (field strength meter).
BB77920-3
HLS-2D Metal Loss Test Procedure
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