21 Nov, 2012 4897 Views Author: root

Spectrophotometer and Colorimeter

When choosing the instrument to purchase or use for the application, it is very important to understand the types of instruments available for measuring color. A colorimeter or spectrophotometer can be used to measure any test substance that is itself colored or can be reacted to produce a color. Both colorimeter and spectrophotometer provide data obtained over the same range of visible wavelengths, but there are some differences when they deal this data.

Explanation
•Colorimeter is an instrument for psychophysical analysis, which measures human eye-brain perception. Colorimetric data can be directly read and provided as tristimulus values.
•spectrophotometer is an instrument for physical analysis. which analyzes the reflecting transmitting properties of objects without human interpretation. Spectrophotometers can indirectly calculate colorimetric information.

Features
•A colorimeter is generally any tool that characterizes color samples to provide an objective measure of color characteristics. In chemistry, the colorimeter is an apparatus that allows the absorbance of a solution at a particular frequency (color) of visual light to be determined. Colorimeters hence make it possible to ascertain the concentration of a known solute, since it is proportional to the absorbance.
•A spectrophotometer is a photometer that can measure intensity as a function of the color, or more specifically, the wavelength of light. There are many kinds of spectrophotometers. Among the most important distinctions used to classify them are the wavelengths they work with, the measurement techniques they use, how they acquire a spectrum, and the sources of intensity variation they are designed to measure. Other important features of spectrophotometers include the spectral bandwidth and linear range. The most common application of spectrophotometers is the absorption.

Components
•Colorimeter is composed of sensor and simple data processor.it has only a set illuminant and observer combination.
•Besides sensor and data processor,spectrophotometer sometimes also includes computer with software. With many available illuminant or observer combinations, it can calculate tristimulus data and metamerism index.

Operations
•Colorimeter uses a tristimulus absorption filter to isolates a broad band of wavelengths. It is generally rugged and less complex instrument than a spectrophotometer.
•Spectrophotometer uses a interference filter or a grating and prism to isolate a narrow band of wavelengths. It is a more complex instrument than a colorimeter.

Usages
•Colorimeter is the optimal choice for quality inspection. It works well in terms of adjusting small color differences under constant conditions and regularly compare similar colors.
•Besides quality inspection,spectrometer is also the optical choice for research and development.It works well in terms of measuring metamerism and observer conditions or variable illuminant and color formulation.

LMS-6000 Pocktable CCD Spectroradiometer