CIH calibrates both noise dosimeters and sound level monitors. Sound level meters are commonly used in noise pollution studies for the quantification of different kinds of noise, especially for industrial, environmental and aircraft noise. Oue current inspection standard meets ISO/IEC 17025:2005 and ANSI S1.4-1983(R2006).
A noise dosimeter is a specialized sound level meter intended specifically to measure the noise exposure of a person integrated over a period of time; usually to comply with Health and Safety regulations such as the Occupational Safety and Health (OSHA) 29 CFR 1910.95. Noise dosimeters measure and store sound pressure levels (SPL) and, by integrating these measurements over time, provide a cumulative noise-exposure reading for a given period of time, such as an 8-hour workday. Dosimeters can function as personal or area noise monitors. In occupational settings, personal noise dosimeters are often worn on the body of a worker with the microphone mounted on the middle-top of the person’s most exposed shoulder.
Regulations (like the 2005 Control of Noise at Work Regulations) state that a sound level meter should be returned every two years and the Acoustic Calibrator every year. However, the more often you have the sound level meter calibrated, the less risk of your measurements being questioned. I always recommend erring on the side of caution, especially when you are measuring to Standards, Regulations and Guidelines.
Equipment manufacturers typically recommend periodic calibration on an annual basis. These rigorous testing protocols ensure that the electronic components are in good working order and detect shifts in performance that indicate gradual deterioration. Periodic calibration results in a calibration certificate documenting the standard of performance. Typically, the instrument will also receive a sticker indicating its last calibration date and when the next periodic calibration is due.