The appendix of EN 12390-1 Standard calls for a set of instruments to be used for dimensional and tolerance verification of the mould and the specimens got from the same.

ZI 2023A Go-Not Go Gauge
For 100 & 150 mm cube moulds

ZI 2023B Rule
Rule straightedge, 300 mm long

ZI 2023C Feeler Gauge
Comprising a set of strips from 0.05 to 0.50 mm, with blade 100 mm long

ZI 2023D Rule Right Angle
Steel made, 150x100 mm, rectangular section

ZI 2023E Digital Vernier Caliper
0-200 mm x 0.01 mm. Readings in mm and inches