FED-STD-228A
Method 8031.1
18 APRIL 2014
YARNS PER INCH, FIBROUS COVERING
1. SCOPE
1.1 This method is intended for use in determining the number of ends (warp yarns) per inch and the
number of picks (filling yarns) per inch in woven tape of insulated wire and cable.
2. SPECIMEN
2.1 Unless otherwise specified in the detail specification, the specimen should be a piece of the tape at
least 6 inches in length and the full width of the tape taken from the inspection unit.
3. APPARATUS AND REAGENTS
3.1 The apparatus and reagents shall be as follows:
3.1.1 A thread counter, pick glass or other suitable instrument consisting of a low power ocular mounted
on a rack and pinion over a graduated scale. The position of the ocular with respect to the scale shall be
indicated by a pointer.
3.1.2 A needle or other pointed instrument.
3.1.3 A 200 ml. beaker with cover glass.
3.1.4 Blotting paper.
3.1.5 Alcohol or other suitable solvent.
4. PROCEDURE
4.1 Warp yarns. Any saturants or finishing materials shall be removed from the specimen by means of
the solvent. The specimen shall then be dried by pressing it between blotting paper and laid out smoothly
on a flat surface without tension. The counting instrument shall be placed on the specimen so that the
graduated edge is at right angles to the yarns to be counted. Starting with the zero graduation of the
scale and the pointer flush with one of the ends (warp yarns), the number of ends (warp yarns) in a
distance of 1 inch of the specimen shall be coupled and the value recorded. If the fabric is 1 inch or less
in width all ends shall be counted and the results expressed as ends (warp yarns) per inch.
4.2 Filling yarns. The number of picks (filling yarns) per inch shall be determined as described in 4.1.
4.3 When more than one tape is present, each tape shall be tested separately.
5. RESULTS
5.1 Unless otherwise specified in the detail specification, two specimens, one from each end of the
inspection unit, shall be tested.
5.2 The ends (warp yarns) per inch of the tape of the inspection unit shall be the average of the results
obtained from the specimens tested.
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