JP3415329B2 - Portable spectrometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to measures the amount of light transmitted through the sample to be measured, relates to a spectroscopic measurement apparatus which calculates a transmittance or absorbance etc. by calculation, in particular, errors in the measurement data due to aging of the light source light quantity The present invention relates to a portable spectroscopic analyzer which can correct and correct transmittance or absorbance so as to be measured and calculated.

[0002]

Conventionally, when calculating the amount of transmitted light was measured transmittance or absorbance etc. sample to be measured, the transmitted light quantity of the reference sample or measuring the amount of reflected light, then also the amount of transmitted light of the sample to be measured the amount of reflected light is measured, the reflectance from the measurement results, the transmittance or was determined by calculating the absorbance or the like.

[0003]

In general, the light source used in this type of spectroscopic analyzer has a tendency that the amount of light changes as the temperature of the light source rises over time after lighting. is there. Was although I, in order to light quantity as a reference is changed, in particular, the measurement sample, such as test measuring equipment and portable measuring devices such as replacing manually, measuring the amount of light transmitted through the reference If a large time difference between the time of measuring the amount of light transmitted through the time and the sample to be measured occurs, will produce a difference in the amount of source light in the transmitted light amount and the measurement time of the sample to be measured for reference. That is , a measurement error due to the light amount difference of the light source occurs. However <br/> also the temperature and the rate of rise of light sources for largely different environmental conditions, are presented solely can not easily be corrected by such adding a constant correction, such as the lighting elapsed time. However, in general, data of the reference light measured I also the difference - by using the data value (R) and transmitted light quantity value of the sample to be measured (S) have absorbance or the like obtained by the following equation Was.

[0004]

(Equation 1) As described above, in the conventional spectroscopic measurement, since the light source light amount at the time of measurement is different, the obtained value includes an error. In order to eliminate such an error, it is indispensable to simultaneously measure the light source light amount and the transmitted light amount of the measured sample simultaneously under the same light source light amount of the reference sample and the measured sample. However, if this is to be realized, a plurality of light amount detectors or a temperature sensor would be required, which would complicate the device, and would be difficult to achieve, for example, the increase in the number of light amount detectors would make the entire device expensive. Many elements remained.

[0005] From the above, in the present invention, in order to correct an error in measurement data due to a temporal change in the light source light amount in the spectroscopic analysis, without increasing the load on the measurement operator , the measuring device having a simple structure, in which the provision of spectroscopic measurement apparatus provided with a correction means to the technical problem.

[0006]

According to the present invention, 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. spectroscopic measuring device by inserting the sample to be measured by measuring the amount of light transmitted through the sample, and the transmittance or absorbance of the sub <br/> sample to be calculated by the arithmetic unit between the light source and the light amount detecting device Wherein the arithmetic unit is a unit
From multiple direct light quantities (Rn) measured every time,
Of the change in the amount of light with respect to the lighting time of
The light intensity characteristic line predicted from the light amount change is determined, and
At the time when the amount of transmitted light (S) of the sample is measured.
Calculate the direct light amount (R ') of the light source
(R ′) and the sample transmitted light amount (S)
Technical means of calculating the transmittance or the absorbance of the sample.

[0007]

[0008]

According to the present invention, a light source and a single light amount detection device for detecting the 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 placed between the light source and the light amount detection device. inserted by measuring the amount of light transmitted through the sample, the spectroscopic measurement apparatus to calculate the or transmittance of the sample to be measured computing device such as absorbance, the burden on the operations, such as measurement operator aware without putting it spectroscopic measurement apparatus for predicting direct light amount of the light source from direct light amount measurement and the measured value at the time of transmission light amount measurement of a sample of the light source to perform before and after or in one of the transmitted light quantity measurement sample to be measured As a result, a spectroscopic measurement apparatus capable of obtaining more accurate measurement results can be provided at low cost.

[0009] will be described in detail, the first light intensity detector, the sample transmitted light intensity when measured by inserting the sample to be measured (S), or before and after measuring the amount of light transmitted through the該被measurement sample in either, A plurality of direct light amounts (Rn) obtained by directly measuring the light source were measured every unit time. For example , a plurality of direct light amounts (R1
After measuring the ~Rn), and measuring the amount of transmitted light by inserting a sample to be measured (S). At this time, the interval between the last direct light amount measurement time and the measured sample measurement time is the same 3 seconds.

[0010] More specifically, after power-on of the spectroscopic measurement apparatus, the measurement is started working with pressing operation by the measurement start button of the operator. Initially, a plurality of direct light amounts (R1 to Rn)
Is automatically measured on the device side, and the last direct light amount (Rn)
When the measurement is completed, the operator is notified of the end by a signal such as a lamp or a display. After confirming this signal, the operator opens the cover for shielding the light amount detecting device within 3 seconds and inserts the sample to be measured. By closing it, the amount of transmitted light (S) can also be measured per unit time. If the operator exceeds 3 seconds, an error message is displayed, and the operator operates the measurement start button again to repeat the operation . Thus, the operator only needs to wait for the signal and insert the sample to be measured, without having to consider the temperature characteristics of the light source. By the way , this measuring operation process can also be performed as follows. That is, after power-on of the spectroscopic measurement apparatus, cover that shields the light quantity detector section - the open by closure by inserting a sample to be measured, or light amount detecting device senses the insertion of the sample to be measured, or The measurement of the transmitted light amount (S) of the sample to be measured is started by sensing that the sample to be measured is inserted by the measurement operator pressing down the measurement button or the like. When the measurement of the sample to be measured is completed, the operator is notified of the completion by a signal such as a lamp or a display, and after confirming this signal, the operator removes the sample to be measured within 3 seconds and covers the sample.
After that , a plurality of direct light amounts (R1 to Rn) are measured at intervals of 3 seconds including the measurement time of the sample to be measured. The object of the present invention is achieved even in such a working process.

[0011] The measurement of the direct light amount may be I line before and after measuring the amount of light transmitted through the sample to be measured. Also, work done by the transmitted light quantity measurement of the actual sample to be measured, the operation of inserting the sample to be measured between the light source and the light quantity detection device, the external light from entering the light quantity detecting apparatus by inserting the sample to be measured This is the work of closing the cover specification that covers the screen, and the other direct light quantity measurement can be easily and automatically realized by the measuring device, so that all the work is completed very easily. .

[0012] Next, the light amount measured in the manner described above in the arithmetic unit is computed processed as follows. That is ,
A plurality of direct light amounts (R) measured before and after the sample to be measured
n) Since the value is measured every unit time together with the sample to be measured, if it is assumed that the change in the light amount of the light source due to the temperature rise is linear, a plurality of direct light amounts and the transmission light amount of the sample to be measured are measured. It can be assumed that the direct light amount of the light source is on a straight line having the same linear light amount characteristic. It was but <br/>, in the present invention, was measured before and after the measurement of the sample to be measured, to make a prediction equation from the amount of light changes with respect to the unit time of the plurality of direct light amount, directly at the time being measured sample to be measured Predict the light amount value. 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, reflectance, transmittance or calculates the absorbance or the like can know the exact values, as in the prior art, the amount of light emitted from the sample to be measured - and the time of obtaining the data - and the time of obtaining the data, the light amount de as a reference Compared to a technique in which a time difference is caused and no consideration is given to the light source light amount that changes with the passage of time, the present invention makes it possible to know the direct light amount of the light source at the time when the sample to be measured is measured. Therefore, the accuracy or reliability of the obtained data is greatly improved.

[0013]

EXAMPLES Hereinafter, a preferred embodiment of the present invention, by irradiating near infrared light to the leaves, per spectroscopic measuring device for measuring and calculating the component obtained from the absorbance and the absorbance, and FIG. 1 A description will be given based on FIG. FIG. 1 is a side sectional view of a main part of the spectroscopic analyzer 1. In Figure 1, the light source 10 is provided on the body 7 of the lower part, the photodiode of the light quantity detecting apparatus 11 in the upper - and has a respective <br/> provided configuration the de 9. Light source 10, a different wavelength peak on the same circumference - made by disposing a plurality of LED2 with click,
Each of the LEDs 2 is provided with a narrow band filter-3 having a different wavelength band. The wavelength band is from 600 nm to 1100
In nm, a narrow band filter-3 having an arbitrary specific wavelength related to a component obtained from this wavelength band is selected. Each LE
The light emitted by D2 is converted into light of a specific wavelength by the narrow band filter 3, and is incident on the scattering plate 4 through which the light is transmitted.
Within the thickness of the scattering plate 4, light is diffused and the directivity is lost. Light became name rather directional leaving the scattering plate 4 enters the condenser block 5 formed inside the conical scattering walls of diffusing action, the light-collection block within 5, the condenser block 5 The light enters the light amount detection device 11 from the transparent glass plate 6 while repeatedly reflecting and diffusing the space surrounded by the scattering plate 4. The light quantity detection device 11 is fixedly provided at an arbitrary distance from the light source 10, more specifically, at a distance between the light source 10 and the transparent glass plate 6 of the light source 10 so that the sample leaf 19 to be measured can be inserted. I have.

Further , an upper lid 12 is provided on the outer periphery of the upper part of the light amount detecting device 11, and an arm 16 extended from the upper lid 12 is
3 for pivoting. When a push button 15 is provided to loosely fit on the main body 7 and press down the arm 16 of the upper lid 12,
To Tomo, coil for urging in a direction opposite to the said push-button 15
A spring 17 is provided. A switch 18 for detecting that the push button 15 has been pressed is provided on the main body 7 facing the push button 15.

Next, a description will be given based on a block diagram of the spectroscopic analyzer 1 with reference to FIG. The transmitted light amount of the measured sample leaf 19 detected by the measuring unit 8 including the light source 10 and the light amount detecting device 11 is converted into an analog electric signal by the photodiode 9 . The photodiode is connected to the analog board 20. The light source 10 is provided with a light emitting device 29 of the LED 2. Analog board
In de 20 performs V / F conversion or A / D conversion from analog to digital signals, or from the voltage to frequency. The converted signal is input to a CPU board 22 including an arithmetic unit via an I / O board 21. A signal for emitting the LED2 is output from the analog board 20 to the light emitting device 29. The I / O board 21 has a measurement result,
The liquid crystal display calculation results or displays the operation instruction LCD2
3, the initial de - key and manipulate or enter data - board - de 24, and de with an external device - to input and output data RS2
A 32C connection port 25 and the like are provided. These CPUs
The board 22 and the I / O board 21 are connected to a power supply board 26. The printer 28 has a printer I / F board.
It is connected to the CPU board 22 through the board 27.

[0016] The spectroscopic analysis and measurement apparatus 1 configured as described above.
Then, the light source 10 and a single light amount detecting device 11 for detecting the amount of incident light of a specific wavelength are opposed 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. Te measured amount of transmitted light of the sample 19, transmission or CPU board absorbance like sample to be measured -
In the spectroscopic measurement apparatus 1 that is calculated by the
Measured when without imposing a burden, such as the measurement worker consciousness, when the transmitted light quantity measurement of sample leaves obtained by the sample measurement and the measured value of the direct light amount of regular light source by the apparatus side of the measuring system The predicted value of the direct light amount of the light source has made it possible to provide a low-cost spectroscopic measurement apparatus capable of obtaining more accurate measurement results.

Next , the calculation processing of the transmitted light amount measurement value of the sample to be measured and the direct light amount measurement value of the light source will be described along the measurement procedure. After turning on the power of the spectroscopic analyzer 1, the measuring operation is started when the operator presses the measurement start button or turns on the power. At this time , insert the reference sample
If the measurement is made and initialized by data obtained from the reference sample, it is an effective means for more accurate measurement.

First, the spectroscopic analyzer 1 directly measures the light intensity of the light source to obtain a plurality of direct light intensity values. A plurality of direct light amount per unit time interval of the time, for example, Ru is measured at 3-second intervals. The values at times TR1 and TR2 are R1 and R2. When the measurement of the last direct light amount (R2) is completed, the end is notified to the operator by a signal of a lamp, a display, or the like.
"Please put the measurement sample." In 23 display to confirm such, pressed down the button 15 pressed within 3 seconds
Then, the upper lid 12 for shielding the light amount detecting device 11 is opened, and the sample to be measured is inserted . Then, the push-button 15
Is released to close the upper lid 12, the transmitted light amount (S) of the sample to be measured can be measured at TS after 3 seconds, and can be measured every unit time. If the operator exceeds 3 seconds, an error message is displayed and the operator presses the measurement start button again to repeat the operation from the beginning. In this way the operator, this measurement
Only the operation of inserting the sample to be measured after waiting for the signal from the measuring device has to be performed. The confirmation of the insertion of the sample to be measured can be regarded as the fact that the sample to be measured has been inserted into the measuring device by the operation of the switch 18 sensed by pressing down the push button 15.

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

[0020]

(Equation 2) It was predicted that it could be defined. Of course, the present invention is not limited to this prediction formula, but the prediction formula predicts the direct light value (R ') of the light source at the time of measuring the sample transmitted light amount, which cannot be measured simultaneously with the measurement of the transmitted light amount of the sample leaves. be able to. If the direct light amount value (R ′) of the light source obtained in this way is replaced with (R) in “Equation 1” and the measured transmitted light amount (S) of the sample to be measured is substituted, there is no error. More accurate absorbance can be calculated. Also, the transmittance and the reflectance can be calculated based on these values to obtain accurate values.

By adding a step of measuring the direct light amount of the light source before and after measuring the transmittance of the sample to be measured, the direct light amount of the light source at the time of sample measurement, which cannot be measured simultaneously, can be easily and accurately predicted. it can also only <br/>, without requiring effort therefore the measurement operator, the same contents as the work to date for measuring the sample to be measured, to obtain accurate measurements than ever Is now available.

Incidentally , this measuring operation step can also be performed as follows. That is, after turning on the power of the spectroscopic analyzer 1,
Open button 15 press the upper lid 12 to shield the light quantity detecting apparatus 11 parts, upon sensing that the measured sample 19 is inserted to the light quantity detector 11 by closing by inserting the measured sample 19, the sample to be measured The transmitted light amount (S) of No. 19 is measured. When the measurement of the measured sample 19 is completed, the operator is notified by a signal of the liquid crystal display LCD 23 or the like that the measurement of the transmitted light amount of the measured sample 19 has been completed. After that, a plurality of direct light amounts (R1 to Rn) are measured at intervals of 3 seconds including the measurement of the sample 19 to be measured. The object of the present invention is achieved even in such a working process.

The measurement of the direct light quantity may be performed separately before and after measuring the transmitted light quantity of the sample to be measured. Further, in actual work, when measuring the transmitted light amount of the sample to be measured, inserting the sample into the light amount detection device ,
Sequence by the operations of closing the upper lid 12 so that the external light from entering the light quantity detecting apparatus by inserting the sample to be measured, since it like automatically measured by the measuring apparatus can be easily realized for the measurement of direct light quantity , All work is completed very easily.

[0024]

According to the present invention, the light amount of the light source is measured every unit time, and the light amount characteristic line predicted from the light amount change is determined.
By doing so, it is possible to easily and accurately calculate the direct light amount of the light source that could not be measured at the same time as the sample measurement , and to measure the sample to be measured without requiring the measurement operator to perform such work. With the same content as before, it is now possible to obtain more accurate measurement results.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a spectroscopic analysis and measurement apparatus showing one embodiment of the present invention .

FIG. 2 is a control block diagram of the spectroscopic analyzer.

FIG. 3 is a diagram illustrating a characteristic that a direct light amount value of a light source changes with time.

[Explanation of symbols]

1 Spectroscopic analyzer 2 LED 3 Narrow band filter 4 scattering plate 5 Focusing block 6 Transparent glass plate 7 Body 8 Measurement section 9 Photodiode 10. Light source 11 Light intensity detector 12 Top lid 13 fulcrum 15 push buttons 16 arms 17 coilsSpring 18 Switch 18 19 Leaf to be measured 20 Analog board 21 I / O board 22 CPU board 23 LCD (liquid crystal display) 24 Keyboard 25 connection port 26 Power supply board 27 I / F board 28 Printer 29 Light emitting device

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 21/00-21/01 G01N 21/17-21/61 PATOLIS

Claims (1)

(57) [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. And measure the amount of transmitted light of the sample,
A spectroscopic measurement apparatus to calculate the transmittance or absorbance of the sample in the arithmetic unit, the arithmetic unit,
From a plurality of direct light amounts (Rn) measured per unit time,
While estimating the change in light amount with respect to the lighting time of the light source,
A light amount characteristic line predicted from the light amount change is determined, and
Is the time at which the transmitted light amount (S) of the sample was measured
, Calculate the direct light amount (R ') of the light source at
(R ′) and the sample transmitted light amount (S)
A portable spectroscopic analyzer for calculating the transmittance or absorbance of a light .