
244 Oxygen-Enhanced Combustion
correlates reasonably well with hearing-damage risk in
industry and with subjective annoyance for a wide cat-
egory of industrial and community noises. After apply-
ing the A-scale correction, the unit of sound pressure
level becomes the dBA scale. Figure 11.7 shows a typical
burner noise curve as measured by a noise meter (at
scale) and the result after applying A-scale correction.
The other, less used correction scales are named, as
might be expected, B, C, and D. Referring to Figure 11.8,
one can see that the C-scale is essentially at over the
range of interest and the B-scale lies somewhere between
the A- and ...