The document specifies dimensions and requirements for the finish of testing glasses used in the testing of surfaces of optical components for surface form tolerances.
DIN 58161-1:2002 history
2002DIN 58161-1:2002-04 Testing of optical components - Part 1: Test glasses with flat surface
2002DIN 58161-1:2002 Testing of optical components - Part 1: Test glasses with flat surface