Integrating sphere-based diffuse reflection spectral measurement device, measurement method and correction method

Abstract

The invention discloses an integrating sphere-based diffuse reflection spectral measurement device, a measurement method and a correction method. The measurement device comprises an integrating spheremain body and a switching device, wherein an entrance port, a measurement port and a detection port are formed in the integrating sphere main body; a sample to be measured or a reference standard reflection board is arranged on a light path at the measurement port; and the switching device can switch the sample and the reference standard reflection board at the measurement port. According to themeasurement method, when the measurement device is applied to measurement, the standard reflection board is used as a reference, and the measurement accuracy is improved by adopting a measurement modeof deducting background noise. According to the correction method, an actually measured value obtained by the measurement method and an analog measured value obtained by an analog measurement methodform a training set, and a neural network model is obtained through training, and an error source in an integrating sphere measurement process is corrected through the neural network model, so that the precision of the integrating sphere-based diffuse reflection spectral measurement is further improved.

Description

technical field [0001] The invention relates to the technical field of spectrum measurement, in particular to an integrating sphere-based diffuse reflectance spectrum measurement device, a measurement method and a calibration method. Background technique [0002] The integrating sphere is a device widely used in steady-state light measurement, and it is most widely used in spectral detection applications, especially for solid and liquid diffuse reflectance spectroscopy. The inner wall of the integrating sphere is generally a diffuse reflective coating with high reflectivity. After the light incident on the sphere undergoes multiple diffuse reflections on the inner wall of the sphere, a uniform light intensity distribution is formed on the spherical surface. A photodetector is placed on the inner wall of the sphere to detect To light intensity can represent the uniform distribution of light intensity in the integrating sphere. When using the integrating sphere to measure the...

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Problems solved by technology

On the other hand, after the incident light enters the integrating sphere, two effects will occur due to the opening of the sphere, resulting in measurement errors

First, part of the light will escape through the entrance, causing a certain amount of light loss; second, the reflectivity of each part of the opening, especially the sample placed at the measurement port, is different from the reflectivity of the inner wall of the sphere, which will cause uneven distribution of light inside the sphere

Especially in the case of sample reflectance changes, the degree of inhomogeneous distribution is difficult to estimate directly, and it has a great influence on the measurement of sample diffuse reflectance spectrum

At present, in the instruments and methods of diffuse reflectance spectrum measurement using the integrating sphere device, the influence of the above background noise and the influence caused by the two effects are not considered, so the measurement results often cannot accurately reflect the real reflectance of the sample.

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