GYZJ-250 test disk for use with hardness tester GYZJ-934-1
The GYZJ-250 test disk stamped 87/89 is used to calibrate the upper range of the GYZJ-934-1 hardness tester
GYZJ-250 test disk for use with hardness tester GYZJ-934-1
The GYZJ-250 test disk stamped 87/89 is used to calibrate the upper range of the GYZJ-934-1 hardness tester