vernier-gage

from The Century Dictionary.

• noun A gage or measuring and calipering apparatus to which the principle of the vernier is applied. It usually has the measuring element in two parts which slide past each other in measuring and carry on the contact edges the two graduations of the vernier type.
• noun A form of pressure-recording apparatus in which the indicating needle or arm is fitted with one graduation of the vernier and the fixed dial carries the other.