This document applies to ball tapes and disk tapes to check rim diameters. The rim circumference has to be verified with the measuring tape adjusted on a control ring before.
DIN 7839:1994 history
1994DIN 7839:1994-07 Rim circumference gauges; ball gauges and disk gauges
1994DIN 7839:1994 Rim circumference gauges; ball gauges and disk gauges