Color Filters in Photometry

Abstract

The selection of the proper filter to be used with a specific colored solution, light source, and lightsensitive element is often difficult when the selection is attempted on the basis of a comparison of transmittance curves of filters and transmittance or transmittancy curves of solutions. A method is given here for evaluating the transmittancy factor for a specified light source, filter, solution, and light-sensitive element from data which can be obtained for the characteristics of the combined light source and PHOTOELECTRIC filter photometers are widely used as aids in quantitative analysis, especially in routine analytical procedures involving the application of colorimetric analysis. These photometers employ as light-sensitive elements the photo-, emission cell (or cells) or the photronic (photovoltaic) cell (or cells). Several excellent reviews of these instruments are available (2, 3, 8-15). The instruments use color filters to select

Photometric Methods in Water Analysis

“…For similar reasons, data obtained with two different models of instruments will be in better agreement if both instruments use narrow band passes than if one, or both, instruments use wide band passes. The interaction of light sources, filters, photocells, and colored liquids has been discussed in greater, and more mathematical, detail by Cooper (18). A convenient collection of data on the older types of filters is presented by Snell and Snell (16,Chapter 12).…”

Light Absorption Spectrometry

“…(12) a cam assembly permitting quick selection of cams; (13) a recorder-drum time device;(14) oblique incidence sample holders;(15) retardation-plate flickering in the photometer;(16) an extended wave-length range;(17) a sliding cover for the transmission chamber;(18) variable plotting speeds; (19) a pen drive free of backlash; (20) a sample holder rejecting the specular component; (21) a horizontal sample holder;…”