7
After that, the gas temperature starts increasing which indi-
cates the fire is not extinguished.
All the suppression tests were tabulated. Table 1 sum-
marizes the results of the overall suppression effectiveness.
The effectiveness is determined as the ratio of the number
of positive tests to the total number of tests for each sup-
pression system. Note that the dual agent row accounts for
two sets of experiments where the nozzles used to release
the dry and wet agents were interchanged. The results sug-
gest that the suppression systems using CO2 or wet chemi-
cal agents achieve the least effectiveness, 17%, and zero,
respectively. However, the systems using dry chemical alone
or dry chemical together with wet chemical provided the
highest success rate 100% and 92%, respectively. The water
mist-based system has about an average success rate of 67%.
Table 2, Table 3, and Table 4 summarize the fire sup-
pression results for each fuel type separately to understand
the effect of fuel type on the effectiveness of fire suppres-
sion. In order to determine if there is a statistically signifi-
cant relationship between the fire suppression agents and
whether or not the fire was suppressed, the Fisher’s Exact
Test was applied to each table [5]. The application of the
Fisher’s Test to the suppression results for the diesel fuel and
hydraulic fluid shown in Table 2 and Table 4 lead to p-val-
ues of 0.11 and 0.09, respectively. This indicates that there
is no statistically significant relationship between the sup-
pression agents in extinguishing the diesel fuel or hydraulic
fluid spray fires, although the sample size is small and with
a larger sample size statistically significant results may be
achieved. However, the application of the Fisher’s Exact
Figure 7. Typical gas temperature pattern during a negative suppression test
Table 1. Overall suppression effectiveness results.
Suppressant
Agent
Count of not
Suppressed
Count of
Suppressed
Effectiveness,
%
CO2 5 1 17
Dry chemical 0 6 100
Dual agent 1 11 92
Water mist 2 4 67
Wet chemical 6 0 0
Table 2. Overall suppression effectiveness results for diesel
fuel
Suppressant
Agent
Count
of not
Suppressed
Count of
Suppressed
Effectiveness,
%
CO
2 1 1 50
Dry chemical 0 2 100
Dual agent 0 4 100
Water mist 0 2 100
Wet chemical 2 0 0
After that, the gas temperature starts increasing which indi-
cates the fire is not extinguished.
All the suppression tests were tabulated. Table 1 sum-
marizes the results of the overall suppression effectiveness.
The effectiveness is determined as the ratio of the number
of positive tests to the total number of tests for each sup-
pression system. Note that the dual agent row accounts for
two sets of experiments where the nozzles used to release
the dry and wet agents were interchanged. The results sug-
gest that the suppression systems using CO2 or wet chemi-
cal agents achieve the least effectiveness, 17%, and zero,
respectively. However, the systems using dry chemical alone
or dry chemical together with wet chemical provided the
highest success rate 100% and 92%, respectively. The water
mist-based system has about an average success rate of 67%.
Table 2, Table 3, and Table 4 summarize the fire sup-
pression results for each fuel type separately to understand
the effect of fuel type on the effectiveness of fire suppres-
sion. In order to determine if there is a statistically signifi-
cant relationship between the fire suppression agents and
whether or not the fire was suppressed, the Fisher’s Exact
Test was applied to each table [5]. The application of the
Fisher’s Test to the suppression results for the diesel fuel and
hydraulic fluid shown in Table 2 and Table 4 lead to p-val-
ues of 0.11 and 0.09, respectively. This indicates that there
is no statistically significant relationship between the sup-
pression agents in extinguishing the diesel fuel or hydraulic
fluid spray fires, although the sample size is small and with
a larger sample size statistically significant results may be
achieved. However, the application of the Fisher’s Exact
Figure 7. Typical gas temperature pattern during a negative suppression test
Table 1. Overall suppression effectiveness results.
Suppressant
Agent
Count of not
Suppressed
Count of
Suppressed
Effectiveness,
%
CO2 5 1 17
Dry chemical 0 6 100
Dual agent 1 11 92
Water mist 2 4 67
Wet chemical 6 0 0
Table 2. Overall suppression effectiveness results for diesel
fuel
Suppressant
Agent
Count
of not
Suppressed
Count of
Suppressed
Effectiveness,
%
CO
2 1 1 50
Dry chemical 0 2 100
Dual agent 0 4 100
Water mist 0 2 100
Wet chemical 2 0 0