1) Measuring instrument 
Butyrometer is a measuring instrument used to measure fat content in milk or milk products in general. The method used in the determination is Gerber`s method as invented by Swiss chemist Niklaus Gerber. ...
• (n.) An instrument for determining the amount of fatty matter or butter contained in a sample of milk.
An instrument for determining the amount of butterfat in milk. ... Origin: G. Boutyron, butter, + metron, measure ... (05 Mar 2000) ... 
Bu`ty·rom'e·ter noun [ Latin butyrum butter + -meter .] An instrument for determining the amount of fatty matter or butter contained in a sample of milk. 
Type: Term Pronunciation: byū′ti-rom′ĕ-ter Definitions: 1. An instrument for determining the amount of butterfat in milk.
butyrometer, butyroscope An instrument for determining the amount of butterfat in milk.