Conventional Products—6424 Projected Beam Type Smoke Detector 23
Total obscuration can be converted to percent per foot, assuming uniform
smoke density for the entire length of the beam. The chart below converts
total obscuration to percent per foot at both 30% and 55% sensitivity
settings (Figure 16).
1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
30
40
50
60
70
80
90
100
110
120
130
140
150
160
170
180
190
200
210
220
230
240
250
260
270
280
290
300
310
320
330
= 30% Sensitivity Setting
= 55% Sensitivity Setting
sensgrph
Figure 16: Sensitivity in %/Feet vs. Distance
Assuming Uniform Smoke Distribution
Sensitivity
