JPH07134100A - Near infrared spectroscopy - Google Patents

Abstract

(57) [Summary] [Purpose] To determine the suitability of the calibration curve used in the analysis of ingredients such as grains quickly and easily. [Arrangement] An analyzer for analyzing components of a measurement sample based on a preset calibration curve by irradiation with near infrared rays, etc., and automatically measuring the measurement sample and a known reference sample alternately. The calibration curve of the measurement sample based on the comparison between the target value calculation result of the reference sample and the known data while performing the fitting of each absorbance of the reference sample and the measurement sample to the respective calibration curve. An arithmetic unit for estimating the adequacy of component calculation is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a near-infrared spectroscopic analysis device, and can be used in a grain taste evaluation device and the like.

[0002]

2. Description of the Related Art A calibration curve obtained based on a known sample for calculating the content (target value) of a certain component or the like is an external temperature, humidity, or light source It is easily affected by changes over time. For this reason, conventionally, a sample that has been subjected to a chemical analysis on a regular basis is measured, the "deviation" is confirmed, and the calibration curve is artificially corrected if necessary.

[0003]

[Means for Solving the Problems] An analyzer for analyzing components of a measurement sample or the like based on a preset calibration curve by irradiation with near-infrared rays, the measurement of the measurement sample and a known reference sample Is configured to alternately perform automatic measurement, while performing the fitting of each absorbance of these reference sample and measurement sample to the respective calibration curve, based on the comparison of the target value calculation result of the reference sample and the above known data. The configuration of the near-infrared spectroscopic analysis apparatus is provided with an arithmetic unit that estimates the suitability of the component calculation based on the calibration curve of the measurement sample.

[0004]

[Advantageous effects of the invention] Not only the measurement of the measurement sample but also the measurement of the known reference sample are alternately performed, and the suitability of the calibration curve of the measurement sample is determined while monitoring the deviation of the calibration curve of the reference sample. Therefore, as compared with the conventional regular maintenance, stable accuracy can be secured even in a place where environmental conditions such as outside air temperature and humidity such as an agricultural production site and a vegetable and fruit sorting place are likely to change.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. In FIGS. 1 and 2, 1 is a light source for irradiating a grain sample, 2 is a condensing lens, 3 is a slit, and these are arranged so as to be on the optical axis of the lens 2. Reference numeral 4 is a chopper for passing and blocking light, and 5 is a disk with a filter having a plurality of filters attached thereto. Reference numeral 6 is a reflection mirror, 7 is a sample set disk for setting a grain sample to be measured, and 8 is a photoelectric detector for detecting light.

The chopper 4 is a disk in which light passing portions and light blocking portions are alternately formed for passing and blocking light, and is configured to rotate at a constant speed by the motor 4a during measurement. The filter-equipped disc 5 has six holes at equal distances from the center of the disc at predetermined intervals, and filters 5A to 5F are attached to the respective holes.
It is configured such that it rotates intermittently during measurement by a, and any one of these filters 5A to 5F comes on the optical axis of the lens 2 when it stops. These filters 5A to 5F are designed to absorb a component to be measured in a measurement sample, for example, a predetermined wavelength (for a protein, 2150 n
m, 2170 nm, 2190 nm, etc.) is set so that it transmits near infrared rays.

The sample set disk 7 was filled with a reference reflection plate 9 made of ceramic and a measurement sample crushed to a very small size at a predetermined position on the circumference at a predetermined distance from the center of the disk. Transparent container (cell) 1
0 and transparent containers 11 and 12 filled with reference samples containing known components are provided. This reference sample is set, for example, at the maximum and minimum of the adaptive range of the calibration curve for component measurement. That is, when measuring the protein content of brown rice, the brown rice sample in which the protein content of brown rice is in the minimum range (for example, 8%), and conversely, this is the maximum range (for example, 10%).
%) In the brown rice sample. The sample set disk 7 is rotated by a motor 7a at the time of measurement, and when stopped, these samples are positioned on the reflected light from the reflection mirror 6. The sample is configured so that the reference reflection plate 9, the low range reference sample, the measurement sample, and the high range reference sample can be repeatedly measured in this order.

An amplifier 13 for amplifying a signal, an A / D converter 14 for A / D conversion, and
And a calculator 15 including a microcomputer or the like. The calculator 15 performs various processes such as obtaining the protein content based on the detection value of the photoelectric detector 8 based on a calibration curve stored in advance. The protein content and the like of the grain sample obtained by the computing unit 15 is displayed on the display unit 16 composed of a liquid crystal display unit or the like.

Numerals 17 and 18 are optical systems for guiding the reflected light to the detector 8. The operation of the above example will be described. It is assumed that the disk with filter 5 is at the position shown in the figure and the chopper 4 is rotating at a predetermined speed. At this time, the light emitted from the light source 1 passes through the lens 2 and the slit 3 and is repeatedly blocked and blocked by the chopper 4, and only the near-infrared light having the wavelength set by the filter 5A is transmitted as the transmitted light.
This transmitted light is reflected by the reflection mirror 6 and then projected and emitted toward the reference reflection plate 9 of the sample set disk 7 standing by below.

The reflected light reflected by the reference reflection plate 9 is
The light is received by the photoelectric detector 8 and photoelectrically converted. The photoelectrically converted electric signal is A / D converted by the amplifier 13 and input to the calculator 15. The reflected light from the reference reflection plate 9 is intermittently obtained every time the light passes through the chopper 4. Therefore, the calculator 15 calculates the average value R _0i (i represents a filter) of the plurality of electric signals output from the photoelectric detector 8.

Next, the sample set disk 7 is rotated,
Move the low level reference sample to the emitter. Similarly, an electric signal obtained from the reflected light is measured to obtain an average value R _Li . Further, the measured average values R _Xi and R _Hi of the measurement sample and the high-level reference sample are obtained and stored. Then, the absorbance is determined from each measured value. That is, the absorbance OD _ji = lo
It is calculated by gR _0i / R _ji (j = 0, L, H).

When the absorbance is calculated, the target value y _j is obtained based on the calibration curve that has been set in advance. Where y _j = k
The calculation formula of ₀ + Σ (k _j · OD _ji ) and its constants k ₀ , k _j, etc. are set for each component to be obtained. The target values y _L and y _H of the reference sample thus obtained are compared with the values which are known in advance by chemical analysis or the like and are appropriately stored in the storage device, and the presence or absence of deviation from them is compared. If it is determined that there is no "deviation", the measurement sample is also assumed deviation without or extremely small for the calibration curve for, without in order to display the calculated target value y _X, when there is the "deviation" is The target value y _X is corrected by the “deviation” amount, and the corrected value y ′ _X is displayed.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an apparatus.

FIG. 2 is a perspective view thereof.

FIG. 3 is a block diagram.

FIG. 4 is a flowchart.

[Explanation of symbols]

 1 Light Source 2 Condensing Lens 3 Slit 4 Chopper 5 Disk with Filter 6 Reflecting Mirror 7 Sample Set Disk 8 Photoelectric Detector 9 Reference Reflecting Plate 10, 11, 12 Transparent Container (Cell) 13 Amplifier 14 A / D Converter 15 Computing unit 16 Display

Claims (1)

[Claims] 1. An analyzer for analyzing components and the like of a measurement sample based on a preset calibration curve by irradiation of near infrared rays, wherein the measurement of the measurement sample and a known reference sample are alternately performed. The calibration of the measurement sample based on the comparison between the target sample calculation result of the reference sample and the known data while performing the automatic measurement and fitting the respective absorbances of the reference sample and the measurement sample to the respective calibration curves. A near-infrared spectroscopic analysis device provided with a calculation unit for estimating the suitability of component calculation using a line.