GI initiates a routine that collects data required to calculate Grating Intercept values, which ensure that the two gratings are synchronised during scanning. The routine performs a scan on slits 1 through 5. Data is written to a GIJJJYY.nnn file, and can be processed by the RD_GS.EXE program to calculate the Grating Intercept to ensure that the two gratings are synchronised during scanning operations.

GI and RD_GS.EXE are normally run by as part of factory set-up operations or when problems are experienced with the micrometers or gratings.

GA Routine replaced GS/GI