Noise-control regulations require the workplace to be surveyed regularly to identify harmful noise levels and to determine the noise exposure of each individual.
The initial survey requires the sound level (SPL) to be determined in dB(A), and if any potentially harmful areas are identified the risk to employees has to be determined from measurements of the average sound level (Leq,t) in dB(A) and the absolute peak value (Lpk) in dB(C). The CR:274 octave band sound level meter from Cirrus Research performs all these measurements in parallel, thereby considerably improving the accuracy and speed with which risk assessments may be carried out, as well as allowing the frequency content of the noise to be determined. Simply stepping through the bands gives the momentary, average and maximum level in each octave. This can be used in the provision of appropriate noise-control measures.
The instrument can be supplied as a complete measurement kit which includes a suitable acoustic calibrator, windshield and miscellaneous accessories in a carrying case. Optional Deaf Defier2 software can also be used with the CR:274 to select the most appropriate hearing protection from an extensive database of ear plugs and defenders.