• (n.) A very sensitive modification or application of the thermopile, used for indicating minute changes of radiant heat, or temperature.
Ra`di·o·mi·crom'e·ter (- o*mi*krŏm'e*tẽr) noun [ Radio- + micrometer .] (Physics) A very sensitive modification or application of the thermopile, used for indicating minute changes of radiant heat, or temperature. 
Type: Term Pronunciation: rā′dē-ō-mī-krom′ĕ-tĕr Definitions: 1. A sensitive thermopile designed for the measurement of minute changes in radiant energy.
[n] - radiometer that is extremely sensitive
noun radiometer that is extremely sensitive