A calibrator is a device or tool used to adjust or measure the accuracy of another device or instrument. Some synonyms for calibrator include standard, gauge, meter, tester, comparator, adjuster, and instrumenter. A standard refers to a device or measurement that is accepted as a reference point for accuracy. A gauge is a tool used for measuring the size or quantity of something. A tester is a device that tests the functionality or performance of another device. A comparator is a device used to compare an unknown value to a known value. An adjuster is a tool used to adjust the accuracy of a device. Finally, an instrumenter refers to the person using or operating the calibrator.