wrote:


A dictionary will help:

From Merriam-Webster:

Main Entry:
gauge
Variant(s):
also gage \ˈgāj\
Function:
noun

2: an instrument for or a means of measuring or testing:

Furthermo Many Cessna Information Manuals also use this spelling.
You can too.

http://www.merriam-webster.com/dictionary/gage