(dated) An instrument for measuring and automatically recording the rise and fall of a river.
photovisual
photovisual
adj
(astronomy) Relating to the magnitude of a star as measured by the size of its image on an isochromatic photographic emulsion.
(optics) Of certain achromatic lenses, having the same focus for the actinic and for the brightest of the visual rays.
pluviograph
pluviograph
noun
An instrument for measuring the amount of water that has fallen (i.e. a rain gauge), with a feature to register the data in real time to demonstrate rainfall over a short period, often an automated graphing instrument.
