340
M. Rasinac et al.
Table 8 The results of the
second experiment
Pass
L eq [dBA]
L Fmax [dBA]
1
80.8
84.4
2
81.9
85.5
3
82.7
87.9
4
84.2
89.8
5
85.4
93.0
6
92.0
106.8
7
88.1
98.9
8
88.2
93.8
9
88.2
93.6
10
89.4
93.4
11
89.3
97.0
12
88.4
96.6
Fig. 7 The time variations of L eq [dBA] during the first (left) and the last (right) pass of the cutter
in the second experiment
3.3 The Third Experiment
The third experiment considered dependence of the noise emission on the radial
depth of the cut. The machined workpiece and the SPL during the experiment are
presented in Fig. 8.
The diagram of the time variation shows that the highest level of noise was emitted
while the cutter was approximately half inside the cut. The maximal measured value
of the sound pressure level (L Fmax ) was 94.56 dBA. Later in the process, when the
cutter was inside the cut by the entire diameter, the SPL showed a substantial drop.