The CMR3 calibrated receiver is designed for measuring the performance of audio induction loop systems. The audio output is within plusmn;0.25 dB over the frequency range and where used with a suitable audio analyser such as the Minilyser from Neutrik Ltd, the frequency response and field distribution of the magnetic field from any audio induction loop system can be plotted. Calibrated to provide 0dBu output for a field strength of 400mA/m RMS, in accordance with the international induction loop standard IEC60118-4 it is an essential tool for anyone wishing to assess loop system performance for analyses or certification.