JPH08313431A - Spectroscopic measuring device - Google Patents

Abstract

PURPOSE: To easily and accurately estimate the direct quantity of light at a time of the measurement of a sample to be measured by measuring the direct quantity of light of a light source before or after the quantity of transmitted light of the sample is measured. CONSTITUTION: Before the quantity of transmitted light of a sample leaf 19 to be measured is measured, a plurality of the direct quantities of light of a light source 10 are measured at a unit time (e.g. 3sec) interval to obtain values R1 , R2 . A worker pushes a push button 15 on the basis of the measuring completion signal of the value R2 to open the upper lid 12 closing a quantity-of-light detector 11 to insert the leaf 19. The button 15 is released to close the upper lid 12 and the quantity S of transmitted light of the leaf 19 is measured after 3sec. By processing the obtained values S, R1 , R2 the direct quantity-of-light value R' of the light source 10 at the time of the measurement of the leaf 19 can be estimated by formula R'=2R2 -R1 . Therefore, the quantity-of-light value R' of the light source 10 incaple of being measured simultaneously with the measurement of the quantity S of light of the leaf 19 can be estimated and accurate absorbancy having no error caused by a change with the elapse of time can be operated from the value R'. Transmissivity can be also accurately calculated by the operation of the value R'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spectroscopic analysis measuring device for measuring the amount of transmitted light of a sample to be measured and calculating transmittance or absorbance by calculation. The present invention relates to a spectroscopic analysis measurement device that corrects an error so that accurate transmittance or absorbance can be measured and calculated.

[0002]

2. Description of the Related Art A conventional technique for measuring the amount of transmitted light of a sample to be measured to calculate the transmittance or the absorbance is to measure the amount of transmitted light or the amount of reflected light of a reference sample and then measure the amount of transmitted light or the amount of reflected light of the sample to be measured. The measurement was performed, and the reflectance, the transmittance, the absorbance, or the like was calculated from these measurement results.

[0003]

Generally, it is clear that the light sources used in these spectroscopic analysis measurement devices tend to change in light quantity as the temperature of the light sources rises with the passage of time after lighting. Therefore, because the light source light quantity that is the reference is changing, the time when the reference transmitted light quantity is measured and the measured value are measured, especially in the case of a test measuring device or a portable measuring device that manually replaces the measurement sample. When a large time difference occurs between the time when the transmitted light amount of the sample is measured, the light source light amount at the measurement time of the reference sample and the measurement time of the sample is also changed. That is, the measurement error is caused by the difference in the light amount of the light source. Moreover, since the temperature and rate of rise of the light source vary greatly depending on the environmental conditions, it cannot be easily corrected by simply adding a fixed correction such as the lighting elapsed time. However, in general, the absorbance and the like have been obtained by the following equation using the data value (R) of the reference light measured with a time difference and the transmitted light amount value (S) of the sample to be measured.

[0004]

[Equation 1] As described above, the light amount of the light source at the time of measurement is different, and thus the obtained value includes an error. In order to eliminate such an error, it is essential that the reference sample and the sample to be measured have the same light source light amount, and the light source light amount and the transmitted light amount of the measured sample are simultaneously measured in terms of time. However, if it is attempted to realize this, a plurality of light quantity detectors or a temperature sensor will be provided, which complicates the apparatus, and the number of light quantity detectors and the like will increase, making the apparatus expensive. Many elements remained.

From the above, according to the present invention, in order to correct the error of the measurement data due to the temporal change of the light amount of the light source in the spectroscopic analysis, the measuring device does not increase the burden on the measuring operator and has a simple structure. The technical problem is to provide a spectroscopic analysis measurement device equipped with a correction means.

[0006]

According to the present invention, a light source and a light amount detecting device are arranged so that a light source and a single light amount detecting device for detecting the light amount of a specific wavelength incident from the light source are opposed to each other at an arbitrary interval. A sample to be measured is inserted between and the amount of transmitted light of the sample is measured, and the transmittance or the absorbance of the sample to be measured is a spectroscopic analysis measurement device that is calculated by an arithmetic device, and in the light amount detection device, The transmitted light amount (S) of the measured sample when the measured sample is inserted and measured, and a plurality of direct light amounts of the light source directly measured before or after measuring the transmitted light amount (S) of the measured sample ( Rn) is measured for each unit time, and the arithmetic unit predicts the direct light quantity (R ′) value at the time when the sample to be measured is measured from the plurality of direct light quantity (Rn) values, and Means for solving the above-mentioned problems by providing a spectroscopic analysis measuring device that calculates the transmittance or the absorbance of a sample to be measured from the direct light amount (R ′) value and the amount of transmitted light (S) of the sample to be measured. And

Further, in the arithmetic unit, a light quantity change with respect to the lighting time of the light source is estimated from a plurality of direct light quantities (Rn) measured for each unit time, and a light quantity characteristic straight line predicted from the light quantity change is determined. , The direct light quantity (R ') of the light source at the time when the transmitted light quantity (S) of the sample to be measured is measured
Was calculated, and the transmittance or the absorbance of the measured sample was calculated from the calculated direct light amount (R ′) and the measured sample transmitted light amount (S).

[0008]

According to the present invention, the light source and the single light amount detecting device for detecting the light amount of the specific wavelength incident from the light source are opposed to each other at an arbitrary interval, and the sample to be measured is placed between the light source and the light amount detecting device. In a spectroscopic measurement device that is inserted to measure the amount of transmitted light of the sample and calculate the transmittance or absorbance of the sample to be measured with a computing device, put a work burden on the measurement operator Without, by spectroscopic analysis measuring device before and / or after the transmitted light amount measurement of the sample to be measured by direct light amount measurement of the light source and by predicting the direct light amount of the light source at the time of measuring the transmitted light amount of the sample from the measured value, A spectroscopic measurement device that can obtain more accurate measurement results can now be provided at low cost.

More specifically, first, in the light amount detector, the sample transmitted light amount (S) when the sample to be measured is inserted and measured, and the light source before and / or after the transmitted light amount of the sample to be measured is measured. And a plurality of direct light quantities (Rn) directly measured at each unit time. For example, multiple direct light amounts (R1
˜Rn), the sample to be measured is inserted and the amount of transmitted light (S) is measured. At this time, the interval between the last direct light amount measurement time and the measured sample measurement time is the same 3
Seconds.

More specifically, after the power supply of the spectroscopic analysis measurement device is turned on, the measurement work is started by the operator depressing the measurement start button or the like. At the beginning, a plurality of direct light quantities (R1 to Rn) are automatically measured on the device side, and when the measurement of the last direct light quantity (Rn) is finished, the operator is notified of the end by a signal such as a lamp or a display. The transmitted light amount (S) can also be measured every unit time by opening the cover that shields the light amount detection device portion within 3 seconds after confirming this signal and inserting and closing the sample to be measured. If the operator exceeds 3 seconds, an error is displayed and the operator presses the measurement start button again to repeat the work. Now the operator only has to wait for the signal and insert the sample to be measured,
It is not necessary to consider the temperature characteristics of the light source. By the way, this measuring operation step can also be performed as follows. That is, after the power supply of the spectroscopic analysis measuring device is turned on, whether the light amount detecting device senses the insertion of the sample to be measured by opening the cover that shields the light amount detecting device portion and inserting and closing the sample to be measured,
Alternatively, the amount of transmitted light (S) of the sample to be measured is started by sensing that the sample to be measured has been inserted by the measurement operator pressing the measurement button or the like. When the measurement of the sample to be measured is completed, the operator is notified of the end by a signal such as a lamp or display,
The operator confirms this signal, removes the sample to be measured within 3 seconds, closes the cover, etc., and then includes multiple direct light quantities (R1) at intervals of 3 seconds including the measurement time of the sample to be measured.
~ Rn) is measured. The object of the present invention can be achieved even with such a work process.

The direct light quantity may be measured before and after measuring the transmitted light quantity of the sample to be measured. Also,
The work performed in the actual measurement of the transmitted light amount of the sample to be measured is to insert the sample to be measured between the light source and the light amount detection device and to insert the sample to be measured and shield it so that external light does not enter the light amount detection device. This is the work of closing the cover specification, and all the other work can be completed very easily because it is easy to automatically measure other direct light amounts on the measuring device side.

Next, in the arithmetic unit, each light quantity measured as described above is arithmetically processed as follows. The multiple direct light intensity (Rn) values measured before and after the measured sample are
Since it is measured together with the sample to be measured for each unit of time, assuming that the change in the light amount of the light source due to the temperature rise is linear, there are multiple direct light amounts and the direct light amount of the light source when measuring the transmitted light amount of the sample to be measured. Can be assumed to be on a straight line with the same linear light amount characteristic. Therefore, in the present invention,
A prediction formula is created from the light intensity changes per unit time of a plurality of direct light intensities measured before and after the measurement of the sample to be measured, and the direct light intensity value at the time when the sample to be measured is measured is estimated. By predicting the direct light amount (R ′) value at the time when the sample to be measured is inserted in this way, the direct light amount and the transmitted light amount at the time when the sample to be measured is measured become clear, and from these values, Accurate values can be known by calculating reflectance, transmittance or absorbance.
This is because a time difference is generated between the time when the light amount data is obtained from the sample to be measured and the time when the reference light amount data is obtained, and consideration is given to the light source light amount that changes with time. Since the present invention can know the direct light amount of the light source at the time when the sample to be measured is measured, the accuracy or reliability of the obtained data is greatly improved as compared with the technique which has not been described.

[0013]

As a preferred embodiment of the present invention, FIG. 1 and FIG. 2 are taken as an example of a spectroscopic analysis measuring device for irradiating a leaf with near infrared light and measuring and calculating the absorbance and a component obtained from the absorbance. Will be described. FIG. 1 is a side sectional view of a main part of the spectroscopic analysis measurement device 1. In FIG. 1, a light source 10 is provided in the lower main body 7, and a photodiode 9 as a light amount detecting device 11 is provided in the upper portion.
The light source 10 has a plurality of LEDs 2 having different wavelength peaks arranged on the same circumference, and each LED 2 is provided with a narrow band filter-3 having a different wavelength band. The wavelength band is 600 nm to 1100 nm, and the narrow band filter-3 having an arbitrary specific wavelength related to the component obtained from this wavelength band is selected. The light emitted from each LED 2 becomes a light of a specific wavelength by the narrow band filter-3 and enters the scattering plate 4 through which the light passes. Within the thickness of the scattering plate 4, light diffuses and loses directivity. The light having no directivity emitted from the scattering plate 4 enters a condensing block 5 formed inside a conical scattering wall having a diffusing action, and the condensing block 5
Inside, the space surrounded by the light collecting block 5 and the scattering plate 4 is made to enter the light amount detecting device 11 from the transparent glass plate 6 while repeating reflection and diffusion. Light intensity detector 1
1 is fixed to the light source 10 at an arbitrary interval, and more specifically, is fixed to the glass 6 of the light source 10 with an interval into which a leaf 19 as a sample to be measured can be inserted.

Further, an upper lid 12 is provided on the outer periphery of the upper portion of the light quantity detecting device 11, and an arm 16 extending from the upper lid 12 is pivotally supported by a fulcrum 13. Further, a push button 15 that is loosely fitted to the main body 7 and pushes down the arm 16 of the upper lid 12 is provided, and a coil spring 17 that biases the push button 15 in the opposite direction is provided. The main body 7 facing the push button 15 is provided with a switch 18 for detecting that the push button 15 is pushed down.

Next, a block diagram of the spectroscopic analysis measurement device 1 will be shown and described with reference to FIG. The transmitted light amount of the sample leaf 19 to be measured detected by the measuring section 8 including the light source 10 and the light amount detection device 11 is converted into an analog electric signal by the photodiode 9 and connected to the analog board 20. . The light source 10 is provided with a light emitting device 29 for the LED 2. The analog board 20 performs A / D conversion from analog to digital signal or V / F conversion from voltage to frequency. The converted signal is I / O board 2
It is input to the CPU board 22 including the arithmetic unit via 1. LED2 from analog board 20 to light emitting device 29
A light emission signal is output. In the I / O board 21,
A liquid crystal display LCD23 for displaying measurement results, calculation results or operation instructions, a keyboard 24 for inputting and operating initial data, and an RS23 for inputting / outputting data to / from external devices.
A 2C connection port 25 and the like are provided. The CPU board 22 and the I / O board 21 are connected to a power supply board 26. The printer 28 is connected to the CPU board 22 via the printer I / F board 27.

The spectroscopic analysis measurement device 1 configured as described above
Then, the light source 10 and the single light amount detecting device 11 for detecting the incident light amount of the specific wavelength are opposed to each other at an arbitrary interval, and the sample leaf 19 to be measured is inserted between the light source 10 and the light amount detecting device 11. Then, the amount of transmitted light of the sample 19 is measured, and the transmittance or absorbance of the sample to be measured is measured by the CPU.
In the spectroscopic analysis measurement device 1 which is calculated by the board 22, the direct light amount sample of the light source is periodically sampled by the measurement system on the device side without burdening the measurement operator with the measurement. By the measurement and the predicted value of the direct light amount of the light source at the time of measuring the transmitted light amount of the sample leaf obtained by the measured value, it becomes possible to inexpensively provide a spectroscopic analysis measurement device that can obtain a more accurate measurement result.

Next, the calculation process of the measured value of the transmitted light amount of the sample to be measured and the measured value of the direct light amount of the light source will be described according to the measuring procedure. After the power supply of the spectroscopic analysis measurement device 1 is turned on, the measurement work is started by the operator depressing the measurement start button or turning on the power supply. At this time, if the reference sample is inserted and measured and the data is obtained from the reference sample and initialized, it becomes an effective means for more accurate measurement.

First, the spectroscopic analysis measurement device 1 directly measures the light quantity of the light source to obtain a plurality of direct light quantity values. At this time, the plurality of direct light quantities are measured at unit time intervals, for example, at 3 second intervals, and the values at the times TR1 and TR2 are R1 and R2. When the final measurement of the direct light amount (R2) is completed, the operator is notified of the end by a signal such as a lamp or a display, and the operator displays this signal, for example, "Please insert the measurement sample" on the LCD 23. Within 3 seconds after confirming the condition, the push button 15 is pushed down to open the upper lid 12 that shields the light amount detection device 11 part, the sample to be measured is inserted, the push button 15 is released, and the upper lid 12 is closed to close the sample to be measured. The amount of transmitted light (S) can be measured at the time Ts after 3 seconds and measured every unit time. If the operator exceeds 3 seconds, an error is displayed and the operator presses the measurement start button again and repeats the work from the beginning. Now, the operator need only wait for the signal and insert the sample to be measured. The confirmation of the insertion of the sample to be measured can be regarded as that the sample to be measured can be inserted into the measuring device by the operation of the switch 18 which is sensed by pressing down the push button 15.

The data of the sample transmitted light amount value (S) and the direct light amount value (R1) (R2) thus obtained are processed as follows. Assuming that the light intensity of the light source changes with the lapse of lighting time and the change is linear, if the time TR1, TR2, TS are shown at equal intervals as shown in FIG. 3, the light intensity change of the light source is the direct light intensity value (R1) A linear light quantity characteristic line can be obtained by R2). So if each time interval is equal,

[0020]

[Equation 2] It was predicted that it could be defined as Of course, it is not limited to this prediction formula, but this prediction formula can predict the direct light quantity value (R ′) of the light source at the time of measuring the sample transmitted light quantity that could not be measured simultaneously with the measurement of the transmitted light quantity of the sample leaf. it can. If the direct light amount value (R ′) of the light source obtained in this way is replaced with (R) of “Equation 1” and the measured transmitted light amount (S) of the measured sample is substituted, there is no error. Accurate absorbance can be calculated. Also,
Accurate values can be obtained by calculating the transmittance and the reflectance as well.

By adding a step of measuring the direct light quantity of the light source before and after measuring the transmittance of the sample to be measured, it is possible to easily and accurately predict the direct light quantity of the light source at the time of measuring the sample, which could not be simultaneously measured. In addition, the measurement operator does not need to take the trouble to do so, and it is possible to obtain a more accurate measurement result with the same content as the operation up to now for measuring the sample to be measured.

By the way, this measuring operation step can also be performed as follows. That is, after the power supply of the spectroscopic analysis measurement device 1 is turned on, the upper lid 12 that shields the light amount detection device 11 portion is opened by pressing the push button 15 and inserting and closing the measured sample 19, so that the measured sample 19 is placed on the light amount detection device 11. When the insertion is sensed, the transmitted light amount (S) of the measured sample 19 is measured. When the measurement of the sample to be measured 19 is completed, the operator is informed by the signal of the liquid crystal display LCD 23 or the like that the measurement of the transmitted light amount of the sample to be measured 19 is completed, and the operator confirms this signal and within 3 seconds the sample to be measured 19 is measured.
After that, a plurality of direct light quantities (R1 to Rn) are measured at intervals of 3 seconds including the measurement of the sample to be measured 19. The object of the present invention can be achieved even with such a work process.

The direct light quantity may be measured separately before and after measuring the transmitted light quantity of the sample to be measured. Also, in actual work, when measuring the amount of transmitted light of the sample to be measured, insert the sample into the light amount detection device and insert the sample to be measured and shield the light amount detection device so that external light does not enter. This is a work for closing 12, and it is possible to easily realize the measurement of the other direct light amount automatically on the measuring device side. Therefore, all the work is extremely simple and the work is simple.

[0024]

By adding a step of measuring the direct light quantity of the light source before and after measuring the transmittance of the sample to be measured, it is possible to easily and accurately predict the direct light quantity of the light source at the time of measuring the sample, which could not be measured at the same time. In addition, the measurement operator does not need to take the trouble to do so, and it is possible to obtain more accurate measurement results with the same contents as the previous work of measuring the sample to be measured. It was

[Brief description of drawings]

FIG. 1 is a side sectional view of a spectroscopic analysis measurement device of the present invention.

FIG. 2 is a control block diagram of the spectroscopic analysis measurement device.

FIG. 3 is a diagram showing a characteristic in which a direct light amount value of a light source changes with time.

[Explanation of symbols]

 1 Spectroscopic Analysis Measuring Device 2 LED 3 Narrow Band Filter-4 Scattering Plate 5 Condensing Block 6 Transparent Glass Plate 7 Main Body 8 Measuring Section 9 Photodiode 10 Light Source 11 Light Quantity Detection Device 12 Top Lid 13 Support Point 15 Push Button 16 Arm 17 Coil Spring 18 Switch 18 19 Measured Sample Leaf 20 Analog Board 21 I / O Board 22 CPU Board 23 LCD (Liquid Crystal Display) 24 Keyboard Board 25 Connection Port 26 Power Board 27 I / F Board 28 printer 29 light emitting device

Claims (2)

[Claims] 1. A light source and a single light amount detecting device for detecting a light amount of a specific wavelength incident from the light source are opposed to each other at an arbitrary interval, and a sample to be measured is inserted between the light source and the light amount detecting device. Is a spectroscopic analysis measuring device in which the transmitted light amount of the sample is measured, and the transmittance or the absorbance of the sample to be measured is calculated by an arithmetic device. In the light amount detecting device, the sample to be measured is inserted and measured. The measured sample transmitted light amount (S) at the time and a plurality of direct light amounts (Rn) directly measured by the light source before and / or after the measured sample transmitted light amount (S) are measured for each unit time. The arithmetic unit predicts the direct light intensity (R ') value at the time when the sample to be measured is measured from the plurality of direct light intensity (Rn) values, and the predicted direct light intensity (R') value and the measured value are measured. Sun Le transmitted light amount (S)
A spectroscopic analysis measurement device characterized in that the transmittance or the absorbance of the sample to be measured is calculated from the above. 2. The arithmetic unit estimates a light quantity change with respect to a lighting time of a light source from a plurality of direct light quantities (Rn) measured every unit time, and determines a light quantity characteristic straight line predicted from the light quantity change, The direct light amount (R ′) of the light source at the time when the transmitted light amount (S) of the measured sample is measured, and the measured direct light amount (R ′) and the measured sample transmitted light amount (S) of the measured sample The spectroscopic analysis measurement device according to claim 1, wherein the transmittance or the absorbance is calculated.