A hook and weight assembly should be used to determine the
length of char or destruction of the specimen. The combined mass of
the assembly should be as indicated in Table 1:
Table 1 Mass to tear charred
fabric
| TABLE 1
|
| Mass to tear charred fabric
|
| Mass of fabric being
tested
|
Total mass used to tear
fabric
|
| g/m2
|
g
|
| <200
|
100
|
| 200 – 600
|
200
|
| >600
|
400
|
After all flaming and afterglow on the specimen have ceased,
the length of char or material destruction should be determined immediately.
The length of char in this test is defined as the distance from the
end of the specimen which was exposed to the flame to the end of a
tear made lengthwise in the specimen through the centre of the charred
area in the following manner:
-
.1 The edge of the highest or greatest char penetration
of the sample should be inspected to determine if as a result of thermoplastic
behaviour a thickening of the edge has developed as a result of the
test. If this has occurred a cut should be made, after cooling, only
sufficiently deep to cut through the highest portion of this thickened
edge of the charred specimen.
-
.2 The specimen should be folded parallel to its
length and lightly creased through the maximum visible portion of
the charred length.
-
.3 The hook should be inserted in the specimen,
on one side of the charred area, 8 mm in from the adjacent outside
edge and 8 mm up from the bottom.
-
.4 The specimen should then be grasped with the
fingers on the opposite side of the charred area, and raised gently
until it supports the weight. The specimen will tear through the charred
area until fabric strong enough to carry the load is reached.