Pt. 25, App. F

(5) Thermocouples. Install a 24 American
Wire Gauge (AWG) Type K (Chromel-Alumel)
thermocouple in the test chamber for temperature monitoring. Insert it into the
chamber through a small hole drilled
through the back of the chamber. Place the
thermocouple so that it extends 11 inches
(279 mm) out from the back of the chamber
wall, 111-2 inches (292 mm) from the right side
of the chamber wall, and is 2 inches (51 mm)
below the radiant panel. The use of other
thermocouples is optional.
(6) Calorimeter. The calorimeter must be a
one-inch cylindrical water-cooled, total heat
flux density, foil type Gardon Gage that has
a range of 0 to 5 BTU/ft2-second (0 to 5.7
Watts/cm2).
(7) Calorimeter calibration specification and
procedure.
(i) Calorimeter specification.
(A) Foil diameter must be 0.25 Section0.005 inches
(6.35 Section0.13 mm).
(B) Foil thickness must be 0.0005 Section0.0001
inches (0.013 Section0.0025 mm).
(C) Foil material must be thermocouple
grade Constantan.
(D) Temperature measurement must be a
Copper Constantan thermocouple.
(E) The copper center wire diameter must
be 0.0005 inches (0.013 mm).
(F) The entire face of the calorimeter must
be lightly coated with  - Black Velvet -  paint
having an emissivity of 96 or greater.
(ii) Calorimeter calibration. (A) The calibration method must be by comparison to a like
standardized transducer.
(B) The standardized transducer must meet
the specifications given in paragraph VI(b)(6)
of this appendix.
(C) Calibrate the standard transducer
against a primary standard traceable to the
National Institute of Standards and Technology (NIST).
(D) The method of transfer must be a heated graphite plate.

(E) The graphite plate must be electrically
heated, have a clear surface area on each
side of the plate of at least 2 by 2 inches (51
by 51 mm), and be 1-8 inch Section1-16 inch thick (3.2
Section1.6 mm).
(F) Center the 2 transducers on opposite
sides of the plates at equal distances from
the plate.
(G) The distance of the calorimeter to the
plate must be no less than 0.0625 inches (1.6
mm), nor greater than 0.375 inches (9.5 mm).
(H) The range used in calibration must be
at least 0-3.5 BTUs/ft2 second (0-3.9 Watts/
cm2) and no greater than 0-5.7 BTUs/ft2 second (0-6.4 Watts/cm2).
(I) The recording device used must record
the 2 transducers simultaneously or at least
within 1-10 of each other.
(8) Calorimeter fixture. With the sliding platform pulled out of the chamber, install the
calorimeter holding frame and place a sheet
of non-combustible material in the bottom
of the sliding platform adjacent to the holding frame. This will prevent heat losses during calibration. The frame must be 131-8
inches (333 mm) deep (front to back) by 8
inches (203 mm) wide and must rest on the
top of the sliding platform. It must be fabricated of 1-8 inch (3.2 mm) flat stock steel
and have an opening that accommodates a 1-2
inch (12.7 mm) thick piece of refractory
board, which is level with the top of the sliding platform. The board must have three 1inch (25.4 mm) diameter holes drilled
through the board for calorimeter insertion.
The distance to the radiant panel surface
from the centerline of the first hole ( - zero - 
position) must be 71-2 Section1-8 inches (191 Section3 mm).
The distance between the centerline of the
first hole to the centerline of the second hole
must be 2 inches (51 mm). It must also be the
same distance from the centerline of the second hole to the centerline of the third hole.
See figure 7. A calorimeter holding frame
that differs in construction is acceptable as
long as the height from the centerline of the

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