Figs. 1–3 show the results for the three photoelectric detectors. The tests were
carried out at about twenty different rates of rise of smoke density at flow velocities
of 0.2, 0.45 and 0.8 m/s. Figs. 4–6 show the response of the three ionisation detectors.
Only data points measured at 0.2 m/s were included for the analysis. As we can see
from Eq. (3), the slope of the data set is the characteristic length and the intersection
with the y-axis the static response threshold.