Hygrodeik
A form of psychrometer with wet-bulb and dry-bulb thermometers mounted on opposite
sides of a specially designed graph of the psychrometric tables. It is so arranged that the
intersections of two curves determined by the wet-bulb and dry-bulb readings yield the relative
humidity, dew-point, and absolute humidity.

"psychrometer" is a word I haven't heard for sixty years. Sounds like a psychiatric word but isn't.