Definition of gauge 1 a: a measurement (as of linear dimension) according to some standard or system: such as
(1) : the distance between the rails of a railroad
(2) : the size of a shotgun barrel's inner diameter nominally expressed as the number of lead balls each just fitting that diameter required to make a pound
a 12-gauge shotgun
(3) : the thickness of a thin material (such as sheet metal or plastic film)
(4) : the diameter of a slender object (such as wire or a hypodermic needle)
(5) : the fineness of a knitted fabric expressed by the number of loops per unit width
Comments
This is a slippery slope.
Gage - is usually used as a proper name
Gauge - is a tool used to measure
So I look at it this way if you are having something measured you are gauging something but if you are talking about the tool it self I use Gage.
Just my 2 cents