#hygrometer  measuring instrument for measuring the relative humidity of the atmosphere
  supertype:  measuring_instrument__measuringinstrument__measuring_system__measuringsystem__measuring_device__measuringdevice  instrument that shows the extent or amount or quantity or degree of something
  subtype:  hygrodeik  a wet and dry bulb hygrometer
  subtype:  hygroscope  hygrometer that shows variations in the relative humidity of the atmosphere
  subtype:  psychrometer  a hygrometer consisting of a dry-bulb thermometer and a wet-bulb thermometer; their difference indicates the dryness of the surrounding air

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