The Noise at Work Directive 2003/10/EC : defines the following limit and action values: Exposure Limit Values : ELV, the LEX,8h = 87 dB(A) and LCpeak = 200 Pa respectively. Upper Exposure Action Values, the LEX,8h = 85 dB(A) and LCpeak = 140 Pa respectively. Lower Exposure Action Values, the LEX,8h = 80 dB(A) and LCpeak = 112 Pa respectively. LCpeak is the maximum value of the
C-weighted, instantaneous noise pressure.
See also : Daily Personal Noise Exposure - LEP,d below. LEX,8h is the Leq - Equivalent Continuous Sound Level corrected for the length of the working shift, in this case 8 hours.
Daily Personal Noise Exposure : LEP,d is the averagedA-weighted noise exposure level for a nominal 8-hour working day and is for assessing the noise exposure of a employee during a working day. It is also known as LEX,8h
LEP,d is calculated from the measured sound exposure, the exposure time and a reference time of 8 h.
If the Leq is measured over 8 hours then Leq and LEP,d and LEX,8h would all be the same.
The European Directive recommends LEX,8h is adopted from 2006 onward.
DOHR : Dose per hour - shows the dose profile for each hour.
Dose% is the amount of noise expressed as a percentage of the normal allowable daily collected during a measurement on a worker with a noise dosimeter.
Dose% varies according to National Standards
Dose Badge small device worn by operator to store fluctuating noise levels during working day. Similar to a Dosimeter.
Dose per Hour : DOHR shows the dose exposure over each hour.
Dosimeter a pocket sized instrument designed to be worn during all or part of the day as a personal monitor in order to check an operator's personal exposure to workplace - Noise Dose.
See also : Sound Exposure Meter
The sound exposure (in physical units) for the whole measurement duration of Dose is known as E (Pa².h) Leq = 10 lg(Dose/100 x 8/T) + 85 dBA : where T = measurement time in hours. LEX = 10 lg(Dose/100) + 85 dBA : where T = measurement time in hours.
Noise Dose per Hour shows the dose exposure over each hour.
Noise Dosimeter a pocket sized instrument designed to be worn during all or part of the day as a personal monitor in order to check an operator's personal exposure to workplace noise : see Sound Exposure meter.
NProjDose : Projected Dose uses the current
Noise Dose value, logged during the present measurement, to be projected forward to give the predicted 8 hour period, assuming the sound levels for the remaining time stays the same.
Threshold Level most regulations specify that for the measurement of noise at work, the sound levels below a certain limit (the threshold) should be disregarded. A Noise Dose Meter therefore only sums up the contributions from the levels above the threshold and uses these values to calculate the
Noise Dose parameters.