Improvements in or relating to methods of testing work-pieces for correctness of linear dimensions

712,541. Linear-dimension gauges. SIGMA INSTRUMENT CO:, Ltd. Feb. 26, 1953 [Dec. 17, 1951], No. 29550/51. Class 106 (2) A method of testing nominally identical workpieces for correctness of a linear dimension comprises the steps of firstly constructing a setting master, then measuring the setting master in regard to the dimension and determining the error in the setting master, placing the measured setting master in a comparator and causing the comparator indicating device to indicate the known measured error of the setting master thereby correctly setting up the comparator, and thereafter gauging the work-pieces for inspection as to the dimension, with the use of the comparator just set up. The work-pieces may be cylinders whose external diameters and lengths are to be inspected by means of a turret comparator as described in Specification 712,539 having appropriate fixtures as described in Specification 712,540, each adjusted in relation to the common indicating device by using a measured setting master.