An instrument for determining the thickness of a fold of skin: Dr. Smith told Mary that one way to determine the presence of obesity was to use a device called an adipometer to access the amount of excess fat around her waistline.

An instrument used to measure an individual's hearing ability: An audiometer generates sounds of known frequency and intensity, especially at the level at which a sound becomes audible at a given frequency.

An audiometer is a device for measuring hearing activity for pure tones of normally audible frequencies.