Gauge According to Figure C6 of NF C 61-314

The gauge is used for maximum opening of contact tubes(16A) according to NF C 61-314 Figure C6.

Standard:
NF C 61-314 “Plugs and socket-outlets for household and similar purposes – 6 A /250 V and 16 A/250 V systems” Figure C6

Figure C6 of NF C 61-314