A Continuous Resistance Measuring Device for Detecting Uniformity of Fine Filaments Such as Tungsten

Abstract

As means of performing quality control for W-filaments in their progress of production some equipments have been designed up to the present. Yet auther perceived about the method of infering from non-uniformity of W-filaments from the state of fluctuation of electrical resistance per unit length along the W-filaments, and produced by way of experiment the continuous resistance measuring device for fine filaments such as tungsten filaments. The device is constructed with mercury electrodes to detect the electrical resistance continuously, narrow-band amplifier to cancel the disturbances from stray electric or magnetic fields and the input of which is formed as the bridge circuit to compensate errors caused by the variation of temperature surrounding and recorder to record the fluctuating portion of resistance. As a result of many experiment auther conclued that this equipment might be useful in quality control for W-filaments.