Acoustic Sound Level and Sound Intensity Measurements

SINT Technology s.r.l. Tel: +39.055.8826302 · Fax: +39.055.8826303 · [email protected] · www.sintechnology.com

Determination of sound power levels of noise sources using sound pressure and sound intensity method

Noise is a critical parameter for health and safety and noise exposure must be kept under control. Noise is characteristic of the environment in which we live and is chiefly determined by the presence of man. Whether in a natural environment, a civil or industrial installation, noise requires the intervention of man for it to be kept under control and to limit the impact of noise on daily activities.

SINT Technology can provide a wide range of acoustics services, from reliable measurements to analysis of results and comparison with the limits laid down by the law and international standards, to designing solutions to reduce noise.

Our services are characterised by: SINT Technology operates in va-  the professionalism guaranteed by highly skilled engineering techni- rious areas cians  OIL & GAS  dynamism and flexibility  Energy  willingness to perform testing on the customer's plant in all parts of the  Rail world  Automotive  detailed reporting in accordance with the customer's requirements and  Civil

SINT Technology s.r.l. Tel: +39.055.8826302 · Fax: +39.055.8826303 · [email protected] · www.sintechnology.com

Acoustic Sound Level and Sound Intensity Measurements

Measurement and analysis of noise in industry and in the workplace

The risk of noise hazards depends primarily on the sound power level present in the workplace and on the length of daily exposure. Prolonged exposure to high noise levels can cause not only hearing impairment but it also acts as a causal factor for hypertension, acceleration of heart rate, and other chronic conditions, for example, ischaemic heart disease, stress, sleep disorders, etc.. SINT Technology is familiar with the prevention principles (reduction of noise at source, limitation of propagation of sound waves with structural provisions, etc.), the related regulations and compliance requirements of busines- ses and local authorities and is able to provide comprehensive professional services both from the point of view of instrumentation and for technical advice. SINT Technology can provide professional guidance for fulfilment of all the obligations set out in the standards:  Assessment of the level, type and duration of exposure  Comparison with the action values and exposure limit values  Choice of personal hearing protectors with adequate noise reduction  Study, design and implementation of acoustic quieting  Information and training for workers

Measurement and analysis of environmental noise

Environmental noise, understood as unwanted or harmful noise from ou- tside, is spreading both in terms of duration and geographical area. Noise is associated with numerous human activities but it is the noise caused by motor vehicles, trains and aircraft that produces the greatest impact. This is a problem particularly for urban areas; approximately 75% of the popu- lation in Europe lives in cities and the volume of traffic is continuing to grow.

SINT Technology has competent certified engineers and with its technical skill, stock of instruments and experien- ce it is able to carry out the necessary measurements and design the necessary corrective measures.

Measurement of sound power level issued by machinery and plants Sound pressure method  ISO 3743-1 - Acoustics -- Determination of sound power levels of noise sources – Engineering methods for small, movable sources in reverberant fields -- Part 1: Comparison method for hard-walled test rooms  ISO 3744 - Acoustics -- Determination of sound power levels of noise sources using sound pressure -- Enginee- ring method in an essentially free field over a reflecting plane

SINT Technology s.r.l. Tel: +39.055.8826302 · Fax: +39.055.8826303 · [email protected] · www.sintechnology.com

Acoustic Sound Level and Sound Intensity Measurements

Sound intensity method The measurement of sound intensity makes it more straightforward to determine the sound power of a source, particularly as it dispenses with the costly and complicated installation of an anechoic or reverberant room. SINT Technology offers this service in accordance with the latest standards, ie:  ISO 9614-1 - Acoustics -- Determination of sound power levels of noise sources using sound intensity -- Part 1: Measurement at discrete points  ISO 9614-2 - Acoustics -- Determination of sound power levels of noise sources using sound intensity -- Part 2: Measurement by scanning

The measurement of emitted sound power by the sound intensity method is the ideal solution for complying with the requirements of the directive on the noise emission of outdoor machinery: Executive Order no. 262, of 4 Sep- tember 2002. This directive regulates the acoustic emissions of over 50 types of machines and equipment used outdoors, establishing the procedures that manufacturers have to follow in order to be able to affix the marking indicating conformity to the directive, consisting of the initials “CE” and of indication of the guaranteed noise level.

Advantages  Immunity from background noise ,  improved precision,  identification, isolation and classification of individual noise sources A sound intensity probe measures only the component of sound energy that flows parallel to the axis of the probe. The flow of sound energy towards the probe is measured as positive intensity while the flow of sound energy in the opposite direction is considered negative. When measurements are made with the sound intensity probe on enveloping surface, background sound goes in one side of the surface and out the opposite side. Background noise is therefore cancelled and the measurement includes only the noise that originates inside the measurement area. The effects of the measurement environment are thus eliminated in the same way.

SINT Technology s.r.l. Tel: +39.055.8826302 · Fax: +39.055.8826303 · [email protected] · www.sintechnology.com

Acoustic Sound Level and Sound Intensity Measurements

Measurements on site In the past, accurate measurement of sound power levels required that a machine or component be sent to an anechoic room in an acoustics laboratory The sound intensity method now offers the possibility of performing very accurate measurements at the customer’s plant or premises without interruption to processes or business. Site measurements save time, cut costs and permit iterative tests for research and development applications.

Architectural acoustic design

The acoustic requisites of halls for use by the public are the set of technical specifications that form the basis for the executive design of acoustic works.

It is interesting to note how methods and systems for describing and quantifying the acoustic performance of buildings have been advanced by academics over the years, identifying numerous parameters which are more or less useful for understanding the mechanism that produces the quality necessary for good listening; whe- reas the design issue of how to select the most suitable materials to meet the necessary acoustics and safety requirements is more difficult, considering also existing volumes layouts and architectural form, which have to

SINT Technology s.r.l. Tel: +39.055.8826302 · Fax: +39.055.8826303 · [email protected] · www.sintechnology.com

Acoustic Sound Level and Sound Intensity Measurements

Instrumentation

SINT Technology has a vast array of noise measurement and analysis equipment. The main instruments are:  Class 1 integrating sound level meters  ½ inch microphones  Acoustic calibrators for microphones  Two-microphone sound intensity probe  Sound intensity probe calibrator

Standards Field of application Description Standard Code

Noise emitted by machinery Measurement of emission sound pressure levels at EN ISO 11200 and equipment a work station and at other specified positions EN ISO 11201 EN ISO 11202 EN ISO 11203

EN ISO 11204 Macchine industriali Determination of sound power levels of noise sour- EN ISO 3744 Sorgenti di rumore ces EN ISO 3746 Determination of sound power levels of noise sour- EN ISO 9614-2

Environmental noise Measurement of sound pressure levels DPCM 01/03/1991 L n° 447 26/10/1995

DPCM 14/11/1997 Work environment DM 16/03/1998

DPCM n° 215 16/04/1999

Determination of noise exposure D.Lgs 81/08

UNI 9432

UNI EN ISO 9612

Industrial plants Measurement of industrial noise ANSI/ASME PTC 36

Guide to evaluation of the impact of noise on the UNI 9572 Plants with gas turbines environment in gas turbine installations

Measurement of emitted airborne noise – Enginee- ISO 10494

Rotating electrical machines Test codes for the measurement of airborne noise ISO 1680 Noise emitted by machinery emitted by rotating electrical machines and equipment

SINT Technology s.r.l. Tel: +39.055.8826302 · Fax: +39.055.8826303 · [email protected] · www.sintechnology.com

Via delle Calandre, 63 - 50041 Calenzano (FI) ITALY

Tel: +39.055.8826302

Fax: +39.055.8826303 www.sintechnology.com [email protected]

VAT IT04185870484

Recognitions

SINT Technology’s test laboratory is accredited to standard ISO/IEC 17025:2005 by the Italian accreditation body ACCREDIA with certificate no. 0910

Certification of conformity to the requirements of standard

UNI EN ISO 9001

SINT Technology s.r.l. Tel: +39.055.8826302 · Fax: +39.055.8826303 · [email protected] · www.sintechnology.com