Abstract
The author has made experiments on the measurement of evenness of yarn in three different ways, namely (1) suction yarn guid tube method, (2) caesium photo-cell method and. (3) photo-voltaic cell method, all the apparatus having been designed and constructed in his laboratory. In the suction yarn guide tube method a tube, through which the yarn tested being continuously passed, was connected to a water stream vacuum pump. The air was only sucked in through the guide tube, so that the degree of evacuation depended only on the thickness of yarn with which the tube was filled. Thus the thickness was measured from the partial vacuum read off from the manometer. A recording midi-ammeter was used instead of recording vacuum gauge for the time being. Integrators and counters, which integrated the length and number of occurrence of definite thickness of passing yarn were also provided for. The whole measuring system will be referred to as “Murameter”.
In the other two methods the yarn was passed in front of a slit upon which a beam of light of defirite intensity was projected The thickness of yarn was read off from the electic current converted from the light passing through the slit and falling into the photosensitive element. A hod vacuum valve amplifier was used in the caesium photo-cell method in order to magnify the minute change in the photocurrent due to the change in thickness of yarn. The results of experiments with beam of light may be reported fully in other occasions but the conclusion the author arrived at is that in cases where the accuracy does not play an important role, the Murameter method is the most practical one and satisfies industrial purposes quite well.
In the present paper the characteristics of a water stream vacuum pump, the construction of the Murameter and some simple theory and characteristics of suction yarn guide tubes are explained. The accuracy of some of the tubes was in the order of 90%, which was also the case with the accuracy of the whole system.
The author also deduced the relation betweeh the density and diameter of the yarn, which were given in the form
ρ=Kd-min which ρ and d signified the density and the diameter of the yarn correspondingly, K and m being constants. The value of m was found, in his case, almost equal to unity.
