Dear Editor,
The sufferer who wrote the letter in SN of May 2, 2016 ‘Owner turned machines off before EPA came to measure noise levels’ after a year of complaints to authorities should log the noise levels over a period of time. When the EPA comes they can compare relative intensities to deduce the decibel levels for when they are absent.
The EPA has to operate at certain standards. That is no doubt why they use their sound level meter at the ‘slow’ one-second response time. The letter writer should not be worried about that, because the standards are designed to take the one second into account. It is the standard he should be worried about.
Is there in fact a standard? When I checked at the EPA last year they referred me to the Guyana National Bureau of Standards (GNBS). When I checked there, they had none. So I would be delighted to know that there is now such a standard.
Most of my clients are in industry where noise is generated by their machinery. All lose interest when they realize there is no Guyana standard. All except one. That one was not going to wait on the GNBS. They have exemplary concern for their (mostly Guyanese) workers. They selected the highest standard from the practices my company presented them and I was able to certify their 2016 operations with it.
Sound level instruments have to be calibrated. Was the GNBS meter calibrated? There are calibration attachments that one can get for about US$500. But what if it goes bad? My solution was to calibrate from the original principles of physics. It is very tedious, but it is the only sustainable way. It is no use going to court without calibration and standard. Any competent defence lawyer can get the case thrown out.
Sound level calculations are complicated. Because of their logarithmic base, measured sound levels do not add like ordinary arithmetic: 1 + 1 = 4 and 2 + 2 = 5 in decibels. Operators also have to know how to measure, calculate and interconvert exposure times, time-weighted averages, and dosages. My company, Think Engine Institute and Energy Services, can provide sound level data logging, calibration, certification of standard, and training. Email alfredbhulai@ thinkengineesco.com.
Yours faithfully,
Alfred Bhulai
