compensator

(literally) A party or thing which compensates, pays or otherwise provides a compensation

Any device used to compensate for something, notably to achieve a better balance

A building control device used to deliver the compensation relationship or curve between the air temperature outside a building and the temperature of water or air provided to spaces or zones within the building for purposes of heating or cooling.

(nautical) One of several small magnets placed in the binnacle to neutralize the effect of the ship's metal on the compass