Federal Aviation Administration, DOT

Pt. 25, App. F

spaschal on DSK3GDR082PROD with CFR

for placement in the calibration rig during
burner calibration (figure 5).
(v) Air velocity meter. Use a vane-type air
velocity meter to calibrate the velocity of
air entering the burner. An Omega Engineering Model HH30A is satisfactory. Use a suitable adapter to attach the measuring device
to the inlet side of the burner to prevent air
from entering the burner other than through
the measuring device, which would produce
erroneously low readings. Use a flexible duct,
measuring 4 inches wide (102 mm) by 20 feet
long (6.1 meters), to supply fresh air to the
burner intake to prevent damage to the air
velocity meter from ingested soot. An optional airbox permanently mounted to the
burner intake area can effectively house the
air velocity meter and provide a mounting
port for the flexible intake duct.
(4) Test specimen mounting frame. Make the
mounting frame for the test specimens of 1-8-

inch (3.2 mm) thick steel as shown in figure
1, except for the center vertical former,
which should be 1-4-inch (6.4 mm) thick to
minimize warpage. The specimen mounting
frame stringers (horizontal) should be bolted
to the test frame formers (vertical) such that
the expansion of the stringers will not cause
the entire structure to warp. Use the mounting frame for mounting the two insulation
blanket test specimens as shown in figure 2.
(5) Backface calorimeters. Mount two total
heat flux Gardon type calorimeters behind
the insulation test specimens on the back
side (cold) area of the test specimen mounting frame as shown in figure 6. Position the
calorimeters along the same plane as the
burner cone centerline, at a distance of 4
inches (102 mm) from the vertical centerline
of the test frame.

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