#radiometer  meter to detect and measure radiant energy (electromagnetic or acoustic)
  supertype:  meter.measuring_instrument  any of various measuring instruments for measuring a quantity
  subtype:  Crookes_radiometer  electromagnetic radiometer consisting of a small paddlewheel that rotates when placed in daylight
  subtype:  radiomicrometer  radiometer that is extremely sensitive
  subtype:  Rayleigh_disk  an acoustic radiometer consisting of a light disk suspended from a quartz thread; when exposed to a progressive sound wave its torque can measure velocity

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