Study on some Effects on Shore Hardness Number : (2nd Report) The Effect of Pressing Force of the Measuring Tube

Abstract

In this report, the behaviour of the effect of pressing force of the measuring tube on Shore-hardness number was investigated. Under the general requests for the testing with the Shore scleroscoper being satisfied, and especially attending to free from the effect of velocity of the operating handle with consideration of the result of the last report, using 3 Shore scleroscopes of D-type, and many specimens which were different in hardness or in material, hardness numbers were measured with varieties of pressing force from 0 to 75 kg. As the results, the behaviour of the effect of pressing force of the measuring tube on hardness number was made clear. The critical (minimum) pressing force to free from this effect was decided according only to hardness of the specimen and not to the material or the tester. An exponential relation was existed between the critical pressing force and hardness of the specimen, therefore the critical pressing force increased according to hardness of the specimen. This result was compared with the results published hitherto, and the latter were included the former but few cases.