the world > matter > physics > electromagnetic radiation > heat > [noun] > measurement of heat > instrument (4)
An instrument for measuring the expansion of a solid under the influence of heat. Now historical.
An instrument for measuring actual quantities of heat, or the specific heat of bodies.
Originally: an instrument for measuring the heating power of the sun's radiation. Later more widely: one for measuring the intensity of solar…
a pyrometer which functions by measuring radiant energy.