H AND D SPEED


Meaning of H AND D SPEED in English

|āchənˈdē- noun

Usage: usually capitalized H&D

Etymology: after Ferdinand H urter and Charles D riffield fl 1890

: a number indicating the sensitivity of a photographic emulsion determined by the method of Hurter and Driffield

Webster's New International English Dictionary.      Новый международный словарь английского языка Webster.