Table 9.--"t" test for environmental conditions 



Runs 

 compared 



Dryness 

 j condition 

 ' amount 

 ' retardant 



Rate of spread 



Radiation 



Weight loss 



Average 

 rate of 

 spread 



_ Significance 

 of rate of 

 spread 



Average ; 

 radiation : 



Significance 

 of radiation 



Rate of 

 weight loss 



_ Significance 

 j of rate of 

 ' weight loss 











Ft./min. 



Percent 



BTU/sq.ft./hr. 



Percent 



Lbs . /min . 



Percent 



1 



1/3 I 



2 



ST 



0.222 





6.47 





0. 16 





3 



1/3 II 



2 



ST 



.264 



97.5 



11.42 



99 



.21 



99.5 



2 



1/3 I 



1 



ST 



.435 





12 .27 





.25 





4 



1/3 II 



1 



ST 



.516 



97.5 



15.83 



90 



.34 



95 



3 



1/3 II 



2 



ST 



.264 





11.42 





.21 





5 



1/3 III 



2 



ST 



.502 



97.5 



6.75 



*i 99 



.23 



1 60 



4 



1/3 II 



1 



ST 



.516 





15.83 





.34 





6 



1/3 m 



1 



ST 



1.034 



99.5 



15.38 



2 N.S. 



.41 



2 N.S. 



7 



2/3 I 



2 



ST 



.349 





10.29 





.23 





10 



2/3 II 



2 



ST 



.405 



80 



7.69 



* 3 80 



.27 



80 



8 



2/3 I 



3 



ST 



. 160 





7.78 





.12 





9 



2/3 II 



3 



ST 



.258 



99.5 



7.94 



4 N.S. 



.22 



90 



11 



2/3 I 



2 



LT 



. 169 





5. 10 





. 14 





13 



2/3 II 



2 



LT 



.216 



90 



6.82 



90 



.19 



90 



12 



2/3 I 



1 



LT 



.233 





5.62 





.15 





14 



2/3 II 



1 



LT 



.418 



95 



9.31 



90 



.25 



80 



13 



2/3 II 



2 



LT 



.216 





6. 82 





. 19 





15 



2/3 III 



2 



LT 



.290 



90 



7.28 



5 N.S. 



.16 



♦580 



14 



2/3 II 



1 



LT 



.418 









.25 





16 



2/3 III 



1 



LT 



1.208 



99.5 



17.21 



90 



.42 



90 



17 



F I 



2 



LT 



.205 





5.75 





. 14 





19 



F II 



2 



LT 



.231 



80 



6.53 



80 



.17 



80 



18 



F I 



1 



LT 



.444 





9.21 





.28 





20 



F II 



1 



LT 



.515 



90 



12.33 



95 



.32 



90 



19 



F n 



2 



LT 



.231 





6.53 





.17 





21 



F III 



2 



LT 



.320 



80 



6.35 



6 N.S. 



.19 



6 70 



20 



F II 



1 



LT 



.515 





12.33 





.32 





22 



F III 



I 



LT 



1.711 



90 



15.33 



99.5 



.42 



99.5 



*Significance in the reverse direction. 



1 It appears that data from these two fires are acceptable, the variation being relatively small. It appears the 

 condition of run 5 is critical in that the main agent in the rate of spread is spotting, probably due to the increased 

 wind in condition III. Because of this, the radiation is significantly lower, and the rate of weight loss is not 

 significantly different. 



s Run 6 again spotted, smoldered, dried out, and then burned more intensively. The radiation charts show a 

 continuous increase in the radiation from 5 to 7 feet in all fires of run 6. In run 4 the radiation is more uniform, 

 not showing the obvious increase from 5 to 7 feet. The averages thus are not significantly different. Because of a 

 large variation in run 6 rate of weight loss, there shows no significant difference between runs 4 and 6 rate of 

 weight loss. 



3 Variation was great, more afterburning occurred in run 7, possibly giving a high average radiation. The 

 fires in run 10 had very little afterburn, thus the probable reason for a lower radiation. 



4 Run 9 fires were very sporadic in their burning pattern. Areas of low radiation and large peaks occurred. 

 Run 8 was much more consistent, variation within also exceeded the variation in between. 



5 Variation is large in both radiation and rate of weight loss. One fire of run 15 with a . 10 rate of weight loss 

 is obviously low. Also, since rate of spread was by large fingers, the readings between 3 and 5 feet for rate of 

 weight loss could be low in run 15. (Thus large gains in radiation and weight loss were not shown. The 3- to 5- 

 foot measure does not represent the actual rate of weight loss.) 



Variation within fires on these two runs is greater than variation in between. Radiation not uniform as after- 

 burning occurred extensively in run 21. 



30 



