By which instrument purity of milk is measured?

Question

Which musical instrument was brought to international attention by its use to signify one of the characters in the soundtrack of a 1966 film also containing whistling and yodelling?

Answer 1

A lactometer

It is an instrument that is used to check for the purity of milk by measuring its density. An instrument to find out the content of the water in the milk or to test the richness of the milk is thus termed as 'lactometers'. The lactometer works on the principle of gravity of milk.