gauger
noun
gaug·er ˈgā-jər 
1
: one that gauges
2
chiefly British : an exciseman who inspects dutiable bulk goods
Word History
Etymology
Middle English, "officer who measures casks of wine to be sure that they contain a standard amount," borrowed from Anglo-French gaugeour, from gauger "to gauge entry 2" + -our -er entry 2
First Known Use
15th century, in the meaning defined at sense 1