Sound and Vibration Insulation Treatment and Advice

Determining the sound power for CE, Norsok and ISO certification

NORSOK noise measurements and Data Sheets

The Norwegian government imposes high demands on equipment placed on offshore locations. There are other high demands on the noise emissions of installations in the offshore industry. Before these equipments can be place on ships and drilling platforms the supplier of these installations must submit and completed a NORSOK form

This NORSOK Noise Data Sheets are filled with various technical data, including data on the sound produced by the installation. On the sheets, the maximum sound pressure level is to be filled in at 1 meter from the installation . Also, the maximum sound pressure level which occurs at the workplace during active operation of the installation. In addition, the Noise Data Sheets on the acoustic power source (SWL = Sound Power Level) is to be filled in on the form. The measurement of the acoustic source of a installation is in most cases not easy and requires specific knowledge of acoustics and experience in performing noise measurements. The facilities for the offshore industry often have considerable size and are often built in large halls, where distracting reflections in the walls may occur. Due to the large size of the noise sources and possible environmental disturbances, the power source usually canít be determine precisely by a simple noise measurement. Therefore the power source needs to be measured through a more specialized method.

One of the most accurate methods to measure the acoustic power of a sound source is described in the ISO 3744 standard. Under this method, measurements are performed at various measuring positions spread over an imaginary surface surrounding the measurement on source. Using these measurements, the acoustic power source can be accurately calculated. This takes into account the (large) size of the source and any environmental disturbances.

AV-Consulting has extensive experience in determining the acoustic power source according to ISO 3744 standard and completing NORSOK Noise Data Sheets.

NEN-EN-ISO 9614-1, BS EN 9614-2 and BS EN ISO-9614-4

The ISO-3744 for determining the sound power is based on sound pressure measurements. The ISO 9614 is based on the measurement of sound intensity, this method provides greater accuracy for determining the sound power of a sound source but also requires expensive equipment (sound intensity analyzer) for the measurements. The advantage of this method is that these are ideal for measurements in the field where other noise sources are present.