A nonintermittent senistometer (time-scale exposure machine) with clock-controlled motor drive
R. Davis · Scientific Papers of the Bureau of Standards · 1925
The work of the Bureau of Standards, in studying photographic materials and processes, has a threefold objective, namely, an inquiry regarding the nature and causes of photographic action and phenomena, the application of photography to scientific research, and the standardization of the methods and procedure for testing photographic materials.The sensitometer described in 1. Constant-speed driving motor * 364 2. Comparison of machine speed with clock 366 3.An automatic synchronizer 367 VI.