Heath Consultants Aqua-Scop - Manual (Page 24)

SOUND LEVEL INTENSITY AT DIFFERENT TEST POINTS
(Figure 11)
Example of a Preliminary Detection (Figure 12): After opening valve boxes
on the main at 1, 2 and 3, the valve stems are checked with the Direct
Contact Microphone. At all three valves a small noise is recognized. The
noise at valve 2 is a little bit louder but it is not enough louder to determine
a difference in the intensity of sound. To decide the further direction of
examination, take comparative measurements at curb valve 4, at hydrant
9 and at curb valve 10. While the noise at point 4 is louder, no noise is
heard at point 9 and 10. The search is continued in the direction of point 4.
Further listening at points 5 and 6 shows a small increase of intensity of
sound and a slight decrease at point 7.
(Figure 12)
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