thermopile

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A device consisting of a number of thermocouples connected in series or parallel, used for measuring temperature or generating current.

from The Century Dictionary.

• noun A thermo-electric battery, especially as arranged for the measurement of small quantities of radiant heat. See thermo-electricity.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Physics) An instrument of extreme sensibility, used to determine slight differences and degrees of heat. It is composed of alternate bars of antimony and bismuth, or any two metals having different capacities for the conduction of heat, connected with an astatic galvanometer, which is very sensibly affected by the electric current induced in the system of bars when exposed even to the feeblest degrees of heat.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun An electronic device that converts thermal energy into electrical energy. Usually constructed using a series-combination of thermocouples.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a kind of thermometer for measuring heat radiation; consists of several thermocouple junctions in series