This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. Any of various instruments for comparing a measured property of an object, such as its shape, color, or brightness, with a standard.

n. Any device for comparing a physical property of two objects, or an object with a standard.

n. An electronic device that compares two voltages, currents or streams of data.

n. An instrument or machine for comparing anything to be measured with a standard measure; -- applied especially to a machine for comparing standards of length.

n. An apparatus for making comparisons; especially, an instrument for comparing the lengths of nearly equal bars, either from end to end or between lines engraved upon them.

n.

n. A vessel in which liquid is kept rapidly stirred and at a uniform constant temperature so that thermometers immersed in it must all be maintained at the same temperature. Simultaneous readings of the secondary thermometers and the standard are made, and the corrections to the former are thus determined for a wide range of temperatures.

"The control arm is also called the "comparator arm.""

transfer comparator   

interpolator    op-amp    baseband    multiplexer    inverter    tachometer    integrator    5v    modulator    attenuator