Noise dosimeter

Dosimeters are also used to collect data for use in legal proceedings, development of engineering noise controls, and other industrial hygiene purposes.

When planning to conduct noise exposure measurements, steps must be taken to ensure that the dosimeters are calibrated and operated according to manufacturers' specifications.

It is also necessary to understand the properties of the acoustic environment, the main measurement objectives as they relate to determining the risk to hearing damage, and the limitations associated with the use of dosimeters.

ANSI S1.25 specifies that dosimeters should at least provide the following parameters: Frequency weighting: A-weighting or C-weighting Exponential averaging: F (fast); S (slow) Criterion level: 90, 85, 84, 80, or V (variable) Criterion duration: Hours Threshold level: 90, 80, or V (variable) Exchange rate: 5, 4, or 3 A noise or sound dose is the amount of sound a person is exposed to in a day.

These devices were worn for the full work shift and at the end would give a readout initially in percentage dose, or in some other exposure metric.

These were the most common way of making measurements to meet legislation in the US, but in Europe, the conventional sound level meter was favoured.

The usual method used was to store data in the form of Short Leq, a French concept that helped to bring computers into acoustics.

By the time the PSEM standard was published, many major sound level meter companies – in both Europe and the USA had a dosimeter in their range.

With the accuracy of a type 2 sound level meter, a majority of noise dosimeters measure within ±2 dB A.