The Audio Frequency Induction Loop field strength meter is a calibrated precision measurement device. It provides a complete measurement method according to international standard IEC 60118-4:2006 for loop systems (AFILS) to certify correct output level, frequency response, AGC-function, distortion and general signal sources. The Loop Testing equipment is supplied with a test CD. A Certificate of Conformity has been designed so that an installer, following the simple test procedures supplied with each test kit, can complete the certification for the client. Specification with CD: * Background noise * Flat / A-weighted. * Frequency response * Normalized level with artificial speech * Level with free selectable source * Coverage area * 10 LED's with 30 dB dynamic range. * Range selectable 0, -30 dB Note! To be used with CD player of high quality to reach accurate result.