Back around 1969 I had a job working in a gage calibration lab. Gages are used in manufacturing to test the dimensions of pieces as they complete a step, and come in pairs of Go/NoGo. Gages allowed for very quick tests on the line by operators. Our lab had to verify that the gages were correct. We also calibrated vernier calipers with gage blocks. Also, I did not misspell gage. That is the correct spelling for this type of device.