For accurately measuring blast overpressures from mining and quarrying operations, high-end Sound Level instruments with special accessories are usually needed.
In Western Australia there is a requirement in the WA Environmental Protection (Noise) Regulations 1997 to monitor blasts using instruments capable of measuring much lower frequencies than standard sound level instruments.
To accurately measure the peak level of a blast, very low frequency sound energy contained in the blast must be picked up by the sound level meter, which requires microphones with extremely low frequency capabilities and electronics with very low cut-off frequencies – 2Hz or less.
Brüel & Kjær offers 2250 Sound Level Meter to suitably meet these stringent requirements.
The advantage of these meters is that unlike some dedicated blast monitors that measure only the lower frequencies, the B&K 2250 can be used for all other types of noise assessment (environmental, occupational, industrial) when not being used for blast measurement.
With the appropriate accessories and knowledge of the instrument setup procedures, 2250 users can quickly convert their instruments from standard sound level meters to state-of-the-art air blast overpressure meters in accordance with the WA noise regulations.
NVMS also offers blast monitor users the opportunity to have their B&K meters calibrated at very low frequencies – as required by the regulations – at our Perth calibration laboratory.
For more information on setting up your B&K meter for blast measurements, please contact us.