Citation

Jung K, Fischer A. Safety Sci. 1993; 16(2): 115-127.

Copyright

(Copyright © 1993, Elsevier Publishing)

DOI

unavailable

PMID

unavailable

Abstract

Jung, K. and Fischer, A., 1993. An ISO-test method for determining slip resistance of footwear. Determination of its precision. Safety Science, 16: 115-127.Co-operative tests were conducted by a working group of the "Foot Protection" ISO standardizing committee ISO/TC94/SC3, with the participation of seven countries, using a total of eight test facilities for determining shoe anti-slip characteristics. The underlying examination plan is based on an ISO-draft proposal "The Measurement of the Slip Resistance of Safety, Protective and Occupational Footwear for Professional Use" defining requirements for the testing machines.The friction coefficients (cof) thereby determined, underlay the statistical evaluation. The correlation analysis of the raw data showed that correlation could be established between the measured results from most of the test machines, despite different observed values for different lubricants. While glycerine gives too low friction coefficients, Berol leads to increased ones.Different friction coefficients measured for the right and the left shoe of the same pair are of purely coincidental nature.No correlation was found between the friction coefficients determined for glycerine and Berol. Friction coefficients measured with one of the two lubricants are not transferable to the other lubricant.As to precision of the coefficient of friction data, the absolute repeatibility limit as well as the absolute reproducibility limit for Berol are greater than they are in the case of glycerine; in addition, they depend on the friction coefficient. The test machines reveal a relative repeatibility limit of 10% and a relative reproducibility limit of 70% and 100% respectively, i.e. that there is a 95% reliability of reproducing the same results with the same testing machine within a 10% friction coefficient range whereas the 95% range of the test results obtained with different testing machines comes up to 70% and 100% of the friction coefficient respectively. Although every single machine furnishes results of acceptable accuracy, the measuring results of the various machines differ considerably. In contrast to the first inter-laboratory trial by Jung and Schenk, it was possible to improve the repeatibility limit, while the reproducibility limit became worse.