TSI Quest EDGE EG-4P, Руководство пользователя

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Introduction 1-3
R a n g e o f S o u n d
Sound pressure is measured in decibels, or tenths of a Bel. Sound
pressure level is indicated as dB SPL. Since the human ear can detect
sounds with an extensive range of amplitude, a decibel scale is used to
simplify the measurement results. For example, the ratio between the
threshold of hearing and threshold of pain in the human ear if measured
in true energy is 10,000,000 times! The same range using the dB scale is
0
–140 dB referenced to 20 µPa (Micropascals).
The quietest sound that humans can hear has an amplitude of
approximately 0 dB. Prolonged exposure to sound pressure levels
exceeding 85 dB can cause permanent damage to the ear. Sound levels
in excess of 130 dB are more than the human ear can safely withstand
and can result in serious pain and permanent damage.
W h a t d o t h e S t a n d a r d s S a y ?
Many organizations have studied and analyzed the effects of high sound
exposure on hearing. As a result, standards were developed to regulate
personal noise exposure. In the United States, the Occupational Safety
and Health Administration (OSHA), the Mine and Safety and Health
Administration (MSHA), and the American Conference of Governmental
Industrial Hygienists (ACGIH) have all created regulations and limitations
on total permissible noise exposure. International standards are specified
by the health and safety regulations such as the European Union (EU)
Directive 2003/10/EC. Additionally, the International Electrotechnical
Commission (IEC) IEC-61252 has specific guidelines and regulations to
monitor noise in the workplace.
To access these copyrighted standards, please refer to the following:

OSHA
—
http://www.osha.gov

MSHA
—
http://www.msha.gov

NIOSH
—
http://www.cdc.gov/niosh/topics/noise

ACGIH
—
http://www.acgih.org/

IEC
—
http://www.iec.ch