The study of wavelength accuracy in spectrophotometer based on linear arrays

摘要

In general, the high precise color meter uses spectrophotometer to measure sample's reflection or transmission rate and then calculate all kinds of color parameters. About spectrophotometer, to design the monochrome parts is very important. At present, the spectrophotometer designed for color meter never use grating scanning but linear array sensors. Its advantage is greatly reducing the measuring time and making the miniature and portable instruments possible. This article will select the linear photodiode array as an example to discuss how the relationship among the wavelength λ, the grating parameter d, the incidence angle ψ, the focus length f', and the number of sensitive cells n in the array. We will deduce the formula of them and calculate the theory results. At last we analyze the difference between the real results and the theory results, discuss some reasons and recommend some methods to improve the wavelength accuracy. These formula and methods will be very useful for spectrophotometer design based on linear array sensors.