Operators can be proficient in the use of the stelometer after only a few tests. Take a sample of fibres with a hand comb and then, without touching the fibres, use the sample clip to extract a specimen. Fasten the specimen in a stelometer clamp, which is held in a special vise. A torsion spring in the vise ensures uniform tightening of the fibre clamp. After placing the clamp in the stelometer, release the trigger to start the pendulum, which causes the force and elongation indicators to move across the scales. Take the readings when the indicators stop at the time of break, the breaking force is read, directly from a scale calibrated from 2 to 7 kilograms. The elongation measurement is read from a scale calibrated from 0 to 50%. The instrument compensates for frame distortion effects on elongation and for breaking-force overshoot when light samples are broken at high load rates.
To calculate the tenacity or strength, multiply the ratio of the breaking force to the fibre mass by sample length. The recommended procedures for use of the stelometer are published by the American Society for Testing and Materials. ASTM D 1445, “Breaking strength and Elongation of Cotton Fibres (Flat Bundle Method).” And ASTM D 2524, “Breaking Tenacity of Wool Fibres, Flat Bundle Method – 1/8 in Gauge Length.
Thus HIROSHIMA Stelometer simultaneously measures strength and elongation for a sample of fibres. With these measurements, the quality of fibres can be checked during purchase and production, and adverse effects in preparation stages can be kept to a minimum.