BURNING TEST 



Burning Procedures 



Treated and conditioned fuel beds were removed from the combustion chamber and 

 placed on the weighing system in the wind tunnel. The weighing system, described by 

 George and Blakely (1970), was a multiple point system capable of monitoring a weight 

 loss from to 6 pounds, depending on the fuel type and loading; sensitivity of the 

 system was about ±0.25 percent, or ±0.001 pound. The weighing system utilized trans- 

 ducer-type elements and load cells manufactured by the Statham Instrument Company. The 

 signal from these transducers was summed and averaged to produce a single direct 

 measurable output and then recorded. 



Aprons were placed on all sides of the treated fuel beds and the starter beds to 

 produce uniform airflow over the fuel surfaces. A small tray of ethanol (approximately 

 25 ml.) at the bottom edge of the igniter tray gave uniform ignition at the leading edge. 

 Just prior to test time, a remote controlled electric spark was produced to ignite the 

 ethanol. The positioning of the beds and a schematic of the weighing system are shown 

 in figure 3. The positioning of side aprons and fuel beds during burning is shown in 

 figure 4. 



- STARTER BED 



TEFLON CUSHION 

 OAK SUPPORT BAR 

 TEFLON WASHER 



- HEAT SHIELD 

 -LOAD CELL 



- TRANSDUCER 



LEAD TO SUMMATION 

 a AVERAGING UNIT 



SIGNAL SUMMATION S 

 AVERAGING UNIT 



DERIVATIVE 

 COMPUTER 



ANALOG 



READOUT 



RECORDER 



« W/ 

 '41 



RECORDER 

 W/t 



Figure 3.— ■Multiple strain gage transducer -type weighing system and 

 positioning of starter and treated fuel beds. 



7 



