Abstract
The strength-measuring indicator of the MacKenzie type tester stops automatically at the instant of fiber breakage, but to measure the breaking extension, we have to observe the instantaneous position of the extension-measuring indicator. By combining a spring and a weight, the authors have made a device which automatically stops the extension-measuring indicator at the instant of fiber breakage. The device has been completed by a partial improvement of the existing tester.
The extension-measuring indicator of the new device stops with a lag of about 0.2mm. It lessens the measurer's fatigue, reduces the observer's errors and measures with greater accuracy the value of breaking extension.
