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計測機器 Audiophony PA BM-ControlのPDF ユーザーマニュアルをオンラインで閲覧またはダウンロードできます。Audiophony PA BM-Control 16 ページ。 Magnetic field strenght meter

English

Procedure for receiving

Thanks to the law of February 2005, establishments receiving the public (ERP) are gradually equip-

ping themselves with magnetic induction loops in order to facilitate listening for people with hearing

difficulties. To be effective these systems must be carefully calibrated to verify that the installation

has been made in compliance with standard EN60118-4. We recommend the delivery of a certifi-

cate of conformity to this standard, according to the model enclosed, signed by the installer.

Standard EN 60118-4 of March 2007

This standard defines 4 very precise parameters.

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The peak magnetic field must reach 400mA/m (integration time 0.125ms).

•

Frequency responses should not vary more than 3dB between 100Hz and 5000Hz.

•

The signal-to-noise ratio must be 47 dB (A-weighting).

•

The magnetic field must be uniform throughout the listening area.

To allow a good listening it is necessary to check all these conditions.

The respect of the magnetic field intensity guarantees that the sound intensity is sufficient, the

responses frequency control ensure that the entire sound spectrum is perceived in the same way

and the signal-to-noise ratio measures the impact of interference magnetic disturbances on intelligi-

bility. Despite the installation of adequate equipment, many factors can disturb these parameters:

the presence of metallic structures causes the magnetic field to drop, transformers or current at

50Hz in the proximity cause magnetic noises. The size and the form of the room can make it difficult

to meet the recommended values at all points.

The type-approval procedure

The following procedure is recommended:

About the room, determine the points where the measurements will be taken ( center, extremities,

•

points near metal structures or noise sources).

•

Measurements by the installer, after the adjustment of the installed equipment, of the various

parameters set by the standard.

•

Delivery of this document signed by the installer to the room manager.

Recommendation

Room managers must ensure that, when installing any magnetic induction loop, the installer delivers

this certificate of conformity. Even if the room manager does not have the competence to judge the

result of the measurements, this "installation report" should be able to be consulted at any time for a

possible control by a team of auditors.

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magnetic loops

BM-Control - Magnetic field strenght meter