A New Type Simple RMS Measuring Instrument

Abstract

A new type, simple RMS measuring instrument which can be used with linear scanning microdensitometer was produced.
Using this instrument, we can obtain RMS values directly from two measured voltage values V₁., V₂, by making a reference to a table.
This instrument has a very fast computing speed and can be manipulated easily so that it is sufficiently available even at the manufacturing process.
This instrument can be characterized by its less measuring error, because of a relatively simple construction.
From result of our RMS measurement for two kinds of photographic film it was ascertained that the aperture independent Selwyn's granularity relation was retained except very small scanning aperture.