Laserfiche WebLink
Site TD-1 <br />r. • A-weighted sound levels currently fluctuate but generally <br />i._ <br />I_ show an increase from last September between 7 and IO dBA. <br />t= The octave band data reveal that all mid and high frequency <br />noise levels (particularly from 1 KHz up) have increased <br />C significantly. Since September there has been a 15 d6 <br />increase at 1 KHz and a 19 d6 increment at both 2 KHz and <br />4 KHz. <br />~; Site TD-2 <br />r- Although there is no line of sight from this measuring po- <br />~, <br />`" sition to the baghouse fan, results indicate an increase of <br />I 6 d6 in A-weighted values. This increase is also attributed <br />to the aging of the fan and its stack. The octave band <br />r • profile shows a consistent 5 d6 increment at all frequencies <br />from 250 Hz to 4 KHZ. The sound level at 8 KHz has increased <br />C over 19 d6 since last September. <br />Site TD-3 <br />The observer at this site has an unobstructed line of vision <br />C to the dust collection system. A-weighted sound levels at <br />this site have increased from 69 dBA last September to a <br />C present value of 77 dBA. A comparison of this year's octave <br />band signature with that of last September indicates indi- <br />vidual octave band increments ranging from 6 d6 at 250 Hz up <br />C to 16 d6 at 8 KHz. The most significant increases were <br />between 1 KHz and 4 KHz. <br />_• <br /> <br />