JP7279937B2 - Optical measuring method and processing device - Google Patents

Description

The present invention relates to an optical measurement method capable of expanding the wavelength range in which a photometric quantity can be measured, and a processing apparatus for the optical measurement method.

2. Description of the Related Art Light sources that generate light containing wavelengths other than the visible range, such as the ultraviolet range and the infrared range, are used in various fields. For example, mercury lamps, deuterium lamps, UV-LEDs, etc. that emit light in the ultraviolet region are used for disinfection, sterilization, chemical analysis, resin curing, and the like.

In order to evaluate a light source that emits light including wavelengths outside the visible range, it is necessary to prepare a standard light bulb (standard device) that corresponds to the wavelengths emitted by the light source.

As disclosed in Non-Patent Document 1, the highest ranking of light radiation in Japan is the National Institute of Advanced Industrial Science and Technology (NMIJ: National Metrology Institute of Japan). It is a group of metrological standards. A standard light bulb supplied by NMIJ (or Nippon Electric Meters Inspection Corporation) is used for valuing photometric quantities such as luminous intensity, illuminance, and distributed temperature. Calibration laboratories use standard light bulbs calibrated by NMIJ (or Nippon Electric Meters Inspection Corporation) to calibrate equipment for general users, such as illuminometers, incandescent light bulbs, and fluorescent lamps.

As disclosed in Non-Patent Document 2, for a spectral irradiance standard bulb submitted by a calibration company, a specific standard device is used for each wavelength in the calibration range of 200 [nm] or more and 400 [nm] or less. A spectral irradiance is given, and a specific sub-standard device gives a spectral irradiance for each wavelength in the calibration range from 250 [nm] to 2500 [nm].

In addition, for the luminous intensity standard bulb and total luminous flux standard bulb submitted by the calibration laboratory, luminous intensity measurement for the specified voltage or specified distribution temperature, assuming that the wavelength range is from 360 [nm] to 830 [nm] in the visible region values or total flux measurements are given.

As disclosed in Non-Patent Document 3, in the calibration range of 250 [nm] to 2500 [nm], a halogen bulb for spectral irradiance is used as the light source to be calibrated, and in the calibration range of 250 [nm] or less, is said to use a deuterium lamp. However, the calibration range of the deuterium lamp is 200 [nm] or more and 400 [nm] or less.

As described above, the national standard traceable standard bulb covering from the ultraviolet region to the infrared region is currently limited to (1) the spectral irradiance standard applied to the calibration range of 200 [nm] to 400 [nm] There are only two, a light bulb (deuterium lamp) and (2) a spectral irradiance standard light bulb (halogen lamp) applied to a calibration range of 250 [nm] to 2500 [nm]. The physical quantity assigned to these standard bulbs is the spectral irradiance (unit examples: [W/m ² /nm] or [μW/cm ² /nm]).

Standard light bulbs for which physical quantities other than spectral irradiance are valued include total luminous flux standard light bulbs for which total luminous flux is valued, and luminous intensity standard light bulbs for which luminous intensity is valued.

Photometric quantities such as luminous flux and luminous intensity are calculated by multiplying the corresponding radiant quantities (eg, radiant flux and radiant intensity) by the standard relative luminosity V(λ). Here, since the wavelength range in which V(λ) is defined is the visible region from 360 [nm] to 830 [nm], the calculated luminous flux and luminous intensity also target the visible region, and the ultraviolet region (wavelength 360 [nm] or less) and infrared region (wavelength 830 [nm] or more) cannot be measured.

Therefore, in the ultraviolet region (wavelength of 360 [nm] or less) or the infrared region (wavelength of 830 [nm] or more), if you try to measure the amount of radiation such as radiant flux, a spectral irradiance standard bulb (deuterium lamp or halogen lamp) ) is used to calibrate the measuring equipment to ensure traceability to the national standard.

As an example, as disclosed in Non-Patent Document 4, a method has been proposed in which a spectral irradiance standard bulb is placed outside the integrating sphere to calibrate the apparatus.

Kenichi Kinoshita, "Survey and research on implementation methods for photometric and radiometric standards based on detector responsivity", [online], March 2008, AIST Measurement Standards Report Vol. 7, No. 1, [Searched on October 17, 2019], Internet <URL: https://unit.aist.go.jp/nmij/public/report/bulletin/Vol7/1/V7N1P41.pdf> "JCSS Technical Requirements Application Guidelines Classification related to registration: Light Classification name of calibration method: Luminous intensity standard lamp, etc. (10th edition)", [online], May 26, 2017, Independent Administrative Agency Product Evaluation Technology Fundamental Organization Accreditation Center, [Searched on October 17, 2019], Internet <URL: https://www.nite.go.jp/data/000001491.pdf> "Reference material 1 Implementation of calibration, etc. using specified standard instruments (spectral total radiant flux)", [online], February 16, 2018, 2017 1st Metrology Administration Council Metrology Committee, [October 2019 Search on the 17th of the month], Internet <URL: https://www.meti.go.jp/shingikai/keiryogyoseishin/keiryo_hyojun/pdf/h29_01_s01_00.pdf> "Achievement of Efficient Measurement of LED Total Luminous Flux -Development of Total Luminous Flux LED Calibration Device Based on New Method-", [online], May 2009, Tokyo Metropolitan Industrial Technology Research Institute, TIRI News, May 2009 Month issue, [searched on October 17, 2019], Internet <URL: https://www.iri-tokyo.jp/uploaded/attachment/2602.pdf>

However, since the calibration method disclosed in Non-Patent Document 4 uses an integrating sphere, it is difficult to improve the calibration accuracy.

One object of the present invention is an optical measurement method that enables measurement of the photometric quantity of a sample even in a wavelength range in which a national standard traceable standard bulb is not provided in which physical quantities other than spectral irradiance are valued. etc. is to be provided.

An optical measurement method according to one aspect of the present invention includes turning on a first standard bulb having a spectral irradiance valued for a first wavelength range and measuring the spectral irradiance at a first distance from the first standard bulb. obtaining a first detection result output from a spectrophotometer positioned at a remote location; and spectral irradiance is evaluated for a second wavelength range that overlaps at least partially with the first wavelength range. obtaining a second detection result output from a spectrophotometer arranged at a position separated by a first distance from the second standard light bulb while lighting the second standard light bulb; calculating a first calibration factor based on the spectral irradiance priced for one standard bulb; and calculating a second calibration factor based on the second detection result and the spectral irradiance priced for the second standard bulb. calculating a calibration factor; and calculating, based on the first calibration factor and the second calibration factor, a correction value of the calibration factor for wavelengths in a wavelength range where the first wavelength range and the second wavelength range overlap. , determining a third calibration factor based on at least the first calibration factor and the correction value; illuminating a third standard bulb and a spectrophotometer positioned a predetermined distance from the third standard bulb. and pricing a third standard bulb a photometric quantity based on the third detection result and the third calibration factor.

The step of determining the third calibration coefficient includes the step of determining a correction target section for which a correction value is to be determined in the wavelength range in which the first wavelength range and the second wavelength range overlap; and determining a correction value for the wavelength.

The step of determining the correction target section may include the step of searching for the section in which the amount of deviation between the value of the first calibration coefficient and the value of the second calibration coefficient is the smallest.

The step of determining a correction value for each wavelength included in the correction target section includes calculating the values of the first calibration coefficient and the second calibration coefficient for each wavelength included in the correction target section. A step of determining corresponding correction values by applying weights may be included.

The optical measurement method includes the steps of obtaining a first irradiance produced by a third standard bulb, obtaining a second irradiance produced by an arbitrary sample, a ratio of the first irradiance to the second irradiance and the and obtaining the photometric quantity of the sample based on the photometric quantity priced for the 3 standard bulbs.

A first irradiance may be produced at the inner wall of the integrator by directing light from a third standard bulb into the integrator, and a second irradiance may be produced by directing light from the sample into the integrator. may be generated on the inner wall of the integrator.

The first wavelength range may include the ultraviolet range and the second wavelength range may include the visible range.

A processing apparatus according to another aspect of the present invention provides a first detection result for a first standard bulb having a spectral irradiance valued for a first wavelength range and a spectral irradiance valued for the first standard bulb. means for calculating a first calibration factor based on . A first detection result is obtained by turning on a first standard bulb and using a spectrophotometer placed at a position separated from the first standard bulb by a first distance where the spectral irradiance is measured. The processing unit quantifies the second standard bulb with a second detection result for a second standard bulb in which the spectral irradiance is rated for a second wavelength range that overlaps at least a portion of the wavelength range with the first wavelength range. and means for calculating a second calibration factor based on the spectral irradiance being measured. A second detection result is obtained by turning on the second standard bulb and using a spectrophotometer positioned at a first distance from the second standard bulb. The processing device includes means for calculating, based on the first calibration coefficient and the second calibration coefficient, correction values of the calibration coefficients for wavelengths in a wavelength range in which the first wavelength range and the second wavelength range overlap; means for determining a third calibration factor based on the calibration factor and the correction value; and determining a photometric quantity for pricing the third standard bulb based on the third detection result and the third calibration factor for the third standard bulb. and means to A third detection result is obtained using a spectrophotometer positioned at a predetermined distance from the third standard bulb.

According to one aspect of the present invention, the photometric quantity of a sample can be measured even in wavelength ranges for which national standard traceable standard bulbs are not provided, in which physical quantities other than spectral irradiance are valued.

4 is a flow chart showing the processing procedure of the measurement procedure of the optical measurement method according to the present embodiment; FIG. 4 is a diagram for explaining calibration coefficient determination processing in the optical measurement method according to the present embodiment; FIG. 2 is a cross-sectional view showing a configuration example of a light-receiving head of a measurement system used in the optical measurement method according to the present embodiment; FIG. 4 is a diagram for explaining a method of calculating calibration coefficients in the optical measurement method according to the present embodiment; FIG. 10 is a diagram for explaining how a secondary standard bulb is assigned a photometric quantity in the optical measurement method according to the present embodiment; FIG. 4 is a diagram for explaining measurement of spectral radiant flux of a sample in the optical measurement method according to the present embodiment; Figure 7 shows in more detail the internal structure of the third measurement system shown in Figure 6; FIG. 4 is a diagram showing an example of the spectrum of light generated by a spectral irradiance standard bulb used in the optical measurement method according to the present embodiment; 9 is an enlarged view of an example of the spectrum shown in FIG. 8; FIG. FIG. 4 is a diagram showing an example of uncertainty that occurs in the spectral irradiance standard bulb used in the optical measurement method according to the present embodiment; FIG. 5 is a diagram for explaining the influence of stray light generated on the spectral irradiance standard bulb used in the optical measurement method according to the present embodiment; FIG. 5 is a diagram showing an example of calibration coefficients calculated using a spectral irradiance standard bulb used in the optical measurement method according to the present embodiment; FIG. 4 is a diagram for explaining processing for determining a joint wavelength range in the optical measurement method according to the present embodiment; FIG. 5 is a diagram showing an example of processing for determining a seam wavelength range in the optical measurement method according to the present embodiment; FIG. 10 is a diagram for explaining a process of connecting calibration coefficients in the optical measurement method according to the embodiment; FIG. 10 is a diagram for explaining a processing example of connecting calibration coefficients in the optical measurement method according to the present embodiment; FIG. 2 is a flowchart showing a more detailed processing procedure of step S18 in FIG. 1; FIG. FIG. 5 is a diagram showing an example of calibration coefficients C(λ) synthesized in the optical measurement method according to the present embodiment; 1 is a schematic diagram showing a hardware configuration example of a processing device for realizing an optical measurement method according to the present embodiment; FIG.

Embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are given the same reference numerals, and the description thereof will not be repeated.

<A. Solution>
As mentioned above, since there is no standard total luminous flux bulb available in the non-visible range, the photometric amount of the sample is evaluated by comparing and measuring with a method such as the spherical photometry method using a total luminous flux standard bulb. difficult.

Therefore, in the embodiment of the present invention, a spectral radiant flux standard light bulb that outputs a wavelength range that is not provided by a national standard traceable standard light bulb in which physical quantities other than spectral irradiance are valued is provided. To provide a method capable of evaluating the photometric quantity of a sample using its spectral radiant flux standard bulb while ensuring standard traceability. A spectral radiant flux standard lamp that mainly emits light in the ultraviolet region (220 [nm] to 340 [nm] as an example) will be described below.

Also, as an example of the photometric quantity of a sample, a case of measuring spectral radiant flux or total radiant flux will be described.

<B. Overview of measurement procedure>
First, an overview of the measurement procedure of the optical measurement method according to the present embodiment will be described.

FIG. 1 is a flow chart showing the processing procedure of the measurement procedure of the optical measurement method according to this embodiment. Among the steps shown in FIG. 1, the steps related to arithmetic processing may be executed by a processing device as described later.

Referring to FIG. 1, first, a process of determining calibration coefficients of the measurement system is performed (step S1).

Specifically, a first measurement system is constructed that includes an optical bench, a light receiving head, and a spectrophotometer (or a spectrophotometer) (step S11).

Subsequently, a spectral irradiance standard bulb (deuterium lamp) (hereinafter also referred to as "ultraviolet standard bulb") that is applied to the calibration range of 200 [nm] or more and 400 [nm] or less is attached, and the ultraviolet standard bulb is attached. and the light receiving head are adjusted (step S12). In this state, the standard lamp for ultraviolet is turned on for aging (step S13). After aging, a first detection result output from the spectrophotometer when the standard lamp for ultraviolet light is turned on is obtained (step S14).

In addition, a spectral irradiance standard bulb (halogen lamp) (hereinafter also referred to as a "visible standard bulb") that is applied to the calibration range of 250 [nm] or more and 2500 [nm] or less is attached, and the visible standard bulb and the light receiving The optical axis with the head is adjusted (step S15). In this state, the visible standard lamp is turned on for aging (step S16). After aging, a second detection result output from the spectrophotometer when the visible standard bulb is turned on is obtained (step S17).

A first measurement constructed using the first detection result obtained in step S14, the second detection result obtained in step S17, and the spectral irradiance assigned to the ultraviolet standard bulb and the visible standard bulb. A system calibration factor C(λ) is determined. (Step S18).

It should be noted that the execution order of the processing of steps S12 to S14 and the processing of steps S15 to S17 may be any.

Subsequently, a process of assigning a photometric quantity (spectral radiant flux and/or total radiant flux) to the spectral radiant flux standard bulb (hereinafter also referred to as a "secondary standard bulb") is performed (step S2). Secondary standard bulbs are priced in the ultraviolet region, so they can also be referred to as spectral radiant flux standard bulbs for the ultraviolet.

Specifically, a second measurement system is constructed that includes an optical bench, a goniostage, a light receiving head, and a spectrophotometer (step S21). A secondary standard bulb is then attached to the second measurement system (step S22). In this state, the secondary standard lamp is turned on for aging (step S23). Using the second measurement system, the secondary standard bulb is subjected to luminous intensity distribution measurement to measure the spectral radiant flux of the secondary standard bulb (step S24). This measured spectral radiant flux is assigned to the secondary standard bulb. It should be noted that for secondary standard bulbs, the total radiant flux may be priced instead of or in addition to the spectral radiant flux.

Finally, a measurement of the photometric quantity (spectral and/or total radiant flux) of the sample using a third measurement system is performed (step S3).

Specifically, a third measurement system including an integrator is constructed (step S31). A secondary standard bulb is then attached to the sample window of the integrator (step S32). In this state, the secondary standard lamp is turned on for aging (step S33). After aging, the detection result output from the spectrophotometer when the secondary standard bulb is turned on is acquired as a reference value (step S34).

Subsequently, the secondary standard bulb is removed from the sample window of the integrator, and the sample to be measured is attached to the sample window of the integrator (step S35). In this state, the sample is lit and aged (step S36). After aging, the detection result output from the spectrophotometer when the sample is turned on is obtained (step S37). Based on the reference value obtained in step S34 and the detection result obtained in step S37, the spectral radiant flux of the sample is calculated (step S38). Note that the total radiant flux may be calculated instead of or in addition to the spectral radiant flux. Then, a series of processing ends.

Note that the processing of steps S36 to S38 may be repeated by the number of samples. Further, the execution order of the processing of steps S32 to S34 and the processing of steps S35 to S37 may be any.

<C. Calibration Coefficient Determination Processing (Step S1)>
First, the calibration coefficient determination process (step S1) will be described.

FIG. 2 is a diagram for explaining the calibration coefficient determination process in the optical measurement method according to the present embodiment. As shown in FIGS. 2A and 2B, in the calibration coefficient determination process (step S1), the first measurement system 10 is used to calculate the calibration coefficients for the spectrophotometer 50 and the light receiving head 60. Determine C(λ).

The first measurement system 10 is an apparatus based on an optical bench 12 , and a light receiving head 60 is arranged at a predetermined position by a support member 14 arranged on the optical bench 12 . The optical bench 12 is a jig for fixing the standard light bulb and the light receiving head 60 . The light receiving head 60 is optically connected to the spectrophotometer 50 via a fiber 68 .

The measurement wavelength range of spectrophotometer 50 includes at least the ultraviolet region. The fiber 68 is made of a material (for example, quartz) that is transparent at least in the ultraviolet region, and guides the light incident from one end through the light receiving head 60 to the spectrophotometer 50 .

FIG. 3 is a cross-sectional view showing a configuration example of a light-receiving head of a measurement system used in the optical measurement method according to this embodiment. The light receiving head 60 has a structure suitable for measuring irradiance. Specifically, referring to FIG. 3, the receiving head 60 includes an aperture 62 and a diffuser plate 64 arranged on an optical axis 66 passing through the connection location of the fiber 68 . The light transmitted through the aperture 62 is diffused by the diffuser plate 64 and enters the spectrophotometer 50 via the fiber 68 .

In the state shown in FIG. 2A, the standard ultraviolet light bulb 2 is arranged at a position facing the light receiving head 60 via the base member 16 arranged on the optical bench 12 . The positions of the supporting member 14 and the base member 16 are adjusted so that the standard ultraviolet light bulb 2 and the light receiving head 60 are arranged on the same optical axis. Also, the distance between the standard ultraviolet light bulb 2 and the light receiving head 60 is adjusted to a standard distance R1 (usually 500 [mm]) predetermined for calibration of the standard ultraviolet light bulb 2 . In the state shown in FIG. 2A, the detection result output from the spectrophotometer 50 when the ultraviolet standard lamp 2 is turned on is obtained as the first detection result.

In this way, the ultraviolet standard bulb 2 (first standard bulb) whose spectral irradiance is valued for the calibration range (first wavelength range) of 200 [nm] or more and 400 [nm] or less is turned on, and the ultraviolet A process of acquiring a first detection result output from the spectrophotometer 50 arranged at a position separated from the standard light bulb 2 for spectral irradiance by a standard distance R1 (first distance) is performed. Here, the first wavelength range includes the ultraviolet region.

On the other hand, in the state shown in FIG. 2B, the standard light bulb 4 for visible light is arranged at a position facing the light receiving head 60 via the base member 18 arranged on the optical bench 12 . The positions of the support member 14 and the base member 18 are adjusted so that the standard light bulb 4 for visible light and the light receiving head 60 are arranged on the same optical axis. Also, the distance between the standard visible light bulb 4 and the light receiving head 60 is adjusted to a predetermined standard distance R1 (usually 500 [mm]) for calibration of the visible standard light bulb 4 . In the state shown in FIG. 2B, the detection result output from the spectrophotometer 50 when the visible standard bulb 4 is turned on is obtained as the second detection result.

Thus, the visible standard in which the spectral irradiance is valued for the calibration range of 250 [nm] or more and 2500 [nm] or less (the second wavelength range that overlaps at least part of the wavelength range with the first wavelength range) When the light bulb 4 (second standard light bulb) is turned on, it is output from the spectrophotometer 50 placed at a position separated from the visible standard light bulb 4 by the standard distance R1 (first distance) where the spectral irradiance is valued. A process of acquiring a second detection result is performed. Here, the second wavelength range includes the visible range.

The spectrophotometer 50 outputs a detection result (Sig-Dark) per unit time after dark correction.

A calibration coefficient C _UV (λ) for the standard ultraviolet light bulb 2 is calculated based on the detection result output from the spectrophotometer 50 when the standard ultraviolet light bulb 2 is lit. That is, the process of calculating the calibration coefficient C _UV (λ) (first calibration coefficient) based on the first detection result and the spectral irradiance assigned to the ultraviolet standard bulb 2 (first standard bulb) is performed. be done.

Similarly, based on the detection result output from the spectrophotometer 50 when the standard visible light bulb 4 is lit, the calibration coefficient C _VIS (λ) for the standard visible light bulb 4 is calculated. That is, the process of calculating the calibration coefficient C _VIS (λ) (second calibration coefficient) based on the second detection result and the spectral irradiance assigned to the visible standard bulb 4 (second standard bulb) is performed. be done.

FIG. 4 is a diagram for explaining a method of calculating calibration coefficients in the optical measurement method according to this embodiment. FIG. 4A shows an example of the detection result of the spectrophotometer 50. FIG. FIG. 4(B) shows an example of test values for the standard bulb used for the measurements shown in FIG. 4(A). FIG. 4C shows an example of calibration coefficients calculated from the detection results of the spectrophotometer 50 and the corresponding test values.

The ratio (for each wavelength) of the measured spectrophotometer 50 detection result shown in FIG. 4A to the calibration value for the corresponding standard bulb shown in FIG. Calculated. The calculated calibration coefficient C(λ) includes values for each wavelength.

In the present embodiment, the calibration coefficient C calculated using the spectral irradiance standard bulb (deuterium lamp) (ultraviolet standard bulb 2) applied to the calibration range of 200 [nm] to 400 [nm] _UV (λ) and a calibration coefficient C _VIS ( λ) can be obtained.

By combining these two calibration factors, the calibration factor C(λ) of the measurement system according to this embodiment is determined. One calibration coefficient C(λ) is obtained from the calibration coefficient C _UV (λ) calculated using the standard ultraviolet light bulb 2 and the calibration coefficient C _VIS (λ) calculated using the standard light bulb 4 for visible light. The processing for determining is described in detail later.

<D. Pricing of Photometric Quantity for Secondary Standard Bulb (Step S2)>
Next, the photometric amount pricing for the secondary standard bulb (step S2) will be described.

FIG. 5 is a diagram for explaining how the photometric quantity is assigned to the secondary standard bulb in the optical measurement method according to the present embodiment. As shown in FIG. 5, the second measurement system 20 is used in pricing the photometric quantity for the secondary standard bulb (step S2).

The second measurement system 20 is obtained by partially modifying the structure of the first measurement system 10 shown in FIG. A standard bulb 6 is placed. Since the light receiving head 60, the fiber 68, and the spectrophotometer 50 are the same as those used in the first measurement system 10, the calibration coefficient C(λ) determined in the calibration coefficient determination process (step S1) described above is used as it is. Available.

The secondary standard bulb 6 can be arranged at an arbitrary relative position with respect to the light receiving head 60 by means of the goniometer stage 22 arranged on the optical bench 12 .

More specifically, the goniometer stage 22 includes a first rotating shaft 24 rotatable along a rotating shaft AX1, a holding member 26 supported by the first rotating shaft 24, and a rotating shaft AX2 provided on the holding member 26. and a second rotation axis 28 rotatable along (perpendicular to the rotation axis AX1). The secondary standard bulb 6 is connected with the second rotating shaft 28 . Therefore, the secondary standard bulb 6 is rotatable with respect to the light receiving head 60 along each of the rotation axis AX1 and the rotation axis AX2. The measured distance R2 between the receiving head 60 and the secondary standard bulb 6 remains constant regardless of the rotational state. That is, the goniometer stage 22 is a mechanism for independently rotating the secondary standard bulb 6 along two rotation axes while maintaining a constant distance to the light receiving head 60 .

In this way, the secondary standard light bulb 6 (third standard light bulb) is turned on, and the detection output from the spectrophotometer 50 arranged at a predetermined measurement distance R2 from the secondary standard light bulb 6 is detected. A process of obtaining a result (third detection result) is performed.

Using the detection results obtained in this manner, the spectral radiant flux Φ _ST (λ) of the secondary standard bulb 6 is measured. The procedure and method for measuring the spectral radiant flux Φ _ST (λ) of the secondary standard bulb 6 will be described.

In a state in which the secondary standard bulb 6 and the light receiving head 60 are in an arbitrary relative relationship (angle θ of the rotation axis AX1, angle φ of the rotation axis AX2), the detection result of the spectrophotometer 50 (per unit time after dark correction) signal intensity) is S (λ: θ, φ).

Using the calibration coefficient C(λ) determined in the calibration coefficient determination process (step S1) described above, the spectral irradiance E _ST (λ: θ, φ) [W/m ² ] of the secondary standard bulb 6 is , is represented by the following equation (1).

E _ST (λ: θ, φ)=S(λ: θ, φ)/C(λ) (1)
Since there is an inverse square law E=I/ ^r2 between the irradiance E [W/m ² ] and the radiant intensity I [W/sr], the spectral radiant intensity I ( λ: θ, φ) [W/sr/nm] is expressed by the following equation (2).

_IST (λ: θ, φ) = _EST (λ: θ, φ) x R2 ² (2)
By integrating the spectral radiant intensity I(λ:θ,φ) of the secondary standard bulb 6 over all solid angles, the spectral radiant flux Φ _ST (λ) [W/nm] of the secondary standard bulb 6 can be calculated. That is, the spectral radiant flux Φ _ST (λ) of the secondary standard bulb 6 is given by the following equation (3).

As described above, the goniometer stage 22 of the second measurement system 20 is used to sequentially change the position of the secondary standard bulb 6 with respect to the light receiving head 60, while the detection results (Sig-Dark ) by the reciprocal of the calibration coefficient C(λ) and the square value of the measurement distance R2 are sequentially integrated to calculate the spectral radiant flux Φ _ST (λ) of the secondary standard bulb 6 .

The amount of movement (change in position) of the secondary standard bulb 6 with respect to the light receiving head 60 is appropriately set according to the visual field range of the light receiving head 60 .

Furthermore, the total radiant flux Φ _ST of the secondary standard bulb 6 can be calculated by integrating the spectral radiant flux Φ _ST (λ) of the secondary standard bulb 6 with respect to the wavelength λ.

By the above processing, the valuation of the spectral radiant flux Φ _ST (λ) and the total radiant flux Φ _ST for the secondary standard bulb 6 is completed.

In this way, based on the detection result (third detection result) output from the spectrophotometer when the secondary standard bulb 6 (third standard bulb) is turned on and the calibration coefficient C(λ) (third calibration coefficient) Then, a process of pricing the secondary standard bulb 6 with a photometric quantity (spectral radiant flux Φ _ST (λ) and/or total radiant flux Φ _ST ) is performed.

<E. Measurement of spectral radiant flux of sample (step S3)>
Next, the measurement of the spectral radiant flux of the sample (step S3) will be described.

FIG. 6 is a diagram for explaining the measurement of the spectral radiant flux of the sample in the optical measurement method according to this embodiment. FIG. 7 is a diagram showing in more detail the internal structure of the third measurement system 30 shown in FIG.

As shown in FIG. 6, the third measurement system 30 is used in measuring the spectral radiant flux of the sample (step S3).

The third measurement system 30 functions as a total radiant flux measuring device (spherical photometer), and includes an integrator 32, a light receiving head 60, and a spectrophotometer optically connected to the light receiving head 60 via a fiber 68. 50. FIG. 6 shows the case of measuring the spectral radiant flux of the sample 8 as an example.

More specifically, in the third measurement system 30 the spectral radiant flux and/or total radiant flux of the sample 8 is determined by comparative measurement with a secondary standard bulb 6 whose spectral radiant flux and/or total radiant flux is rated. Measure the bundle.

The inner wall of the integrator 32 is coated with a white diffuse reflector such as barium sulfate (BaSO ₄ ) or Spectralon (registered trademark) (PTFE). The light incident on the integrator 32, or the light generated inside the integrator 32 or the light incident inside the integrator 32 is multiple-reflected by the inner wall of the integrator 32, and the inner wall of the integrator 32 is evenly illuminated. become. Under such conditions, the average irradiance at the inner wall of integrator 32 will be proportional to the total radiant flux of the incident light.

A photometric window 36 is provided in a portion of the inner wall of the integrator 32, in which a transmissive diffusion plate or the like is fitted. A light-receiving head 60 is attached to the photometric window 36 to observe the irradiance of the inner wall of the integrator 32, thereby obtaining a measurement result proportional to the spectral radiant flux or the total radiant flux of the light source.

As the integrator 32, a spherical integrating sphere as shown in FIG. 6 may be used, or a hemispherical integrating hemisphere having a mirror surface may be used.

As shown in FIG. 7 , a light shielding plate 37 may be provided inside the integrator 32 so that the light entering from the sample window 34 does not enter the photometry window 36 directly.

Further, a correction light source 38 for correcting self-absorption may be provided. A correction light source 38 is used to determine a self-absorption correction coefficient α for correcting the influence of light absorption by members existing inside the integrator 32 .

As described above, in step S2, the photometric quantity (spectral radiant flux and/or total radiant flux) is assigned to the secondary standard lamp 6, which is the spectral radiant flux standard lamp for ultraviolet. In the third measurement system 30, the secondary standard bulb 6 and the sample 8 are compared and measured to calculate the photometric quantity (spectral radiant flux and/or total radiant flux) of the sample 8. FIG.

Let _ΦST be the total radiant flux valued for the secondary standard bulb 6, let _SST be the detection result of the spectrophotometer 50 when the secondary standard bulb 6 is turned on, and let SST be the spectrum produced when the sample 8 is turned on. Assuming that the detection result of the photometer 50 is S _SMP , the total radiant flux Φ _SMP of the sample 8 is expressed by the following equation (4).

Φ _SMP =α×S _SMP /S _ST ×Φ _ST (4)
If the shape of the secondary standard bulb 6 and the shape of the sample 8 are substantially the same, it may be considered that the self-absorption correction coefficient α≈1.

Alternatively, considering the detection results for each wavelength (each channel), the spectral radiant flux Φ _SMP (λ) of the sample 8 is expressed by the following equation (5).

Φ _SMP (λ)=α×S _SMP (λ)/S _ST (λ)×Φ _ST (λ) (5)
As shown in FIG. 6A, the secondary standard bulb 6 is attached to the sample window 34 of the integrator 32, and the detection result _SST of the spectrophotometer 50 when the secondary standard bulb 6 is turned on is obtained. Thus, the process of acquiring the irradiance produced by the secondary standard bulb 6 (third standard bulb) is performed. The acquired irradiance is produced on the inner wall of the integrator 32 by letting the light from the secondary standard bulb 6 (third standard bulb) enter the integrator 32 .

Similarly, as shown in FIG. 6B, the sample 8 is attached to the sample window 34 of the integrator 32, and the detection result S _SMP of the spectrophotometer 50 when the sample 8 is lit is obtained. Thus, the process of obtaining the irradiance produced by any sample 8 is performed. The acquired irradiance is produced at the inner wall of the integrator 32 by directing the light from the sample 8 into the integrator 32 .

Using the obtained detection result S _ST and detection result S _SMP and the spectral radiant flux Φ _ST (λ) or the total radiant flux Φ _ST valued for the secondary standard bulb 6, the spectral radiant flux Φ _SMP (λ) or total radiant flux Φ _SMP is calculated. Thus, the ratio between the irradiance obtained for the secondary standard bulb 6 and the irradiance obtained for the sample 8, and the photometric quantity (spectral radiant flux Φ _ST (λ ) or the total radiant flux Φ _ST ), the process of obtaining the photometric quantity of the sample 8 is performed.

The photometric quantity (spectral radiant flux Φ _SMP (λ) or total radiant flux Φ _SMP ) of the sample 8 can be obtained by the above processing procedure.

It is known that the diffuse reflection material (for example, barium sulfate or Spectralon) applied to the inner wall of the integrator 32 gradually decreases in reflectance with aging. Therefore, a process of acquiring the detection result _SST of the spectrophotometer 50 that occurs when the secondary standard bulb 6 is turned on, and a process of acquiring the detection result S- _SMP of the spectrophotometer 50 that occurs when the sample 8 is turned on. It is preferable that there is as little time as possible between Therefore, it is preferable to periodically perform the process of acquiring the detection result _SST that serves as the reference value.

<F. Determining Process of Calibration Coefficient C(λ)>
Next, the processing (step S18) for determining the calibration coefficient C(λ) in the calibration coefficient determination processing (step S1) will be described in detail.

(f1: overall processing)
FIG. 8 is a diagram showing an example of the spectrum of light generated by the spectral irradiance standard bulb used in the optical measurement method according to this embodiment. FIG. 8 shows the normalized light intensity generated by each standard bulb.

Referring to FIG. 8, standard ultraviolet light bulb 2 generates light having a wavelength range from approximately 200 [nm] to 400 [nm]. On the other hand, the visible standard light bulb 4 generates light including a wavelength range of about 250 [nm] or more.

FIG. 9 is an enlarged view of an example of the spectrum shown in FIG. Referring to FIG. 9, the range from 250 [nm] to 400 [nm] is the wavelength range in which the light generated by the standard lamp 2 for ultraviolet and the light generated by the standard lamp 4 for visible overlap.

In the optical measurement method according to the present embodiment, the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ) calculated using the visible standard bulb 4 are combined to synthesize the calibration coefficient C(λ). First, each viewpoint will be explained.

FIG. 10 is a diagram showing an example of uncertainty that occurs in the spectral irradiance standard bulb used in the optical measurement method according to this embodiment. Referring to FIG. 10, the uncertainty of standard lamp 2 for ultraviolet is relatively large compared to the uncertainty of standard lamp 4 for visible. That is, the accuracy of the calibration coefficient C _UV (λ) calculated using the standard ultraviolet bulb 2 is considered to be lower than that of the calibration coefficient C _VIS (λ) calculated using the standard visible bulb 4. .

Therefore, with 250 [nm], which is the lower limit wavelength of the standard light bulb 4 for visible light, as a boundary, the calibration coefficient C _UV (λ) is adopted in the wavelength range below the boundary, and the calibration coefficient C _VIS is adopted in the wavelength range above the boundary. It also seems best to take (λ). However, in the vicinity of the lower limit wavelength of the standard light bulb 4 for visible light, errors due to stray light that can occur inside the spectrophotometer 50 have a large effect.

FIG. 11 is a diagram for explaining the influence of stray light generated on the spectral irradiance standard bulb used in the optical measurement method according to this embodiment. FIG. 11(A) shows stray light produced in the standard lamp 2 for ultraviolet, and FIG. 11(B) shows stray light produced in the standard lamp 4 for visible.

As shown in FIG. 11A, the light generated by the standard ultraviolet light bulb 2 has a higher intensity on the shorter wavelength side, and the influence of stray light is relatively small. As a result, it can be considered that the values of the short wavelength side of the calibration coefficient C _UV (λ) calculated using the ultraviolet standard bulb 2 are more accurate.

On the other hand, as shown in FIG. 11B, the light generated by the standard visible light bulb 4 has a lower intensity on the shorter wavelength side, and the influence of stray light is relatively greater. As a result, it can be considered that the value of the short wavelength side of the calibration coefficient C _VIS (λ) calculated using the visible standard bulb 4 is more inaccurate.

FIG. 12 is a diagram showing an example of calibration coefficients calculated using a spectral irradiance standard bulb used in the optical measurement method according to this embodiment. FIG. 12 shows an example of the calibration coefficient C _UV (λ) calculated using the standard lamp 2 for ultraviolet and the calibration coefficient C _VIS (λ) calculated using the standard lamp 4 for visible.

Among these calibration coefficients, it can be seen that the calibration coefficient C _VIS (λ) calculated using the standard visible light bulb 4 changes sharply on the short wavelength side from 350 [nm]. Such rapid changes in the calibration coefficient are considered to be the effects of stray light that can occur inside the spectrophotometer 50 . According to the calculation example of the calibration coefficient shown in FIG. 12, it can be said that the range up to 250 [nm], which is the lower limit wavelength of the standard light bulb 4 for visible light, cannot be used for calibration.

According to the above studies, the wavelength range (for example, 250 [nm] to 400 [nm]), the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ) are preferably stitched together as appropriate.

As a basic idea for connecting the calibration coefficients, for example, the calibration coefficient C _VIS (λ) calculated using the low-uncertainty visible standard bulb 4 is used as the calibration coefficient C(λ) within a practical range. adopted as In addition, the calibration coefficient C _UV (λ) calculated using the standard ultraviolet light bulb 2 from the lower limit wavelength (for example, 200 [nm]) for which there is no test value for the standard light bulb 4 for visible light and the standard light bulb 4 for visible light are used. The calibration coefficient C _UV (λ) is mainly used for the range up to the wavelength where the calibration coefficient C VIS (λ) calculated in the above manner is close to the value (hereinafter _also referred to as the “joint wavelength range”).

In order to determine the calibration coefficient C(λ) by connecting the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ) in this way, the following two processes are required.

(1) Processing for searching for a joint wavelength range in which the calibration coefficients match or approximate (2) Arithmetic processing for connecting calibration coefficients These processings will be described in detail below.

(f2: search processing for wavelength range (joint wavelength range) where calibration coefficients match or approximate)
The joint wavelength range corresponds to a correction target section in which the correction value of the calibration coefficient is to be determined in the wavelength range in which the wavelength range of the standard lamp for ultraviolet 2 and the wavelength range of the standard lamp for visible 4 overlap. The seam wavelength range search process means a process of determining a correction target section for which the correction value of the calibration coefficient is to be determined.

The seam wavelength range is preferably determined numerically according to a predetermined algorithm, rather than determined visually by the user. In particular, the width of the seam wavelength range varies with the specifications of the standard bulb and spectrophotometer used. Determination by the user's eyes has large variations among users.

FIG. 13 is a diagram for explaining the process of determining the joint wavelength range in the optical measurement method according to this embodiment. Referring to FIG. 13, the calibration coefficient C _UV (λ) calculated using the standard ultraviolet bulb 2 and the calibration coefficient C _VIS (λ) calculated using the standard visible bulb 4 match or approximate each other. The seam wavelength range is preferably evaluated in an interval containing a plurality of continuous calibration coefficients.

For example, when evaluating only one point where the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ) intersect, if there are multiple intersection points, the seam wavelength range is appropriately set. cannot be determined. Therefore, when the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ) intersect at a plurality of points, as shown in FIG. is preferred.

In the example shown in FIG. 13, the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ) intersect at three points. An example is shown in which a total of three points including two points adjacent to each intersecting point are used for evaluation. Evaluating the difference (such as root mean square and sum of squares) of the calibration coefficients of three consecutive points determines which interval is appropriate.

In the example shown in FIG. 13, the section containing the middle intersection point is determined to be appropriate and determined as the seam wavelength range.

More specifically, the matching degree of calibration coefficients may be evaluated according to the root mean square (RMS) as shown in the following equation (6).

In the above equation (6), a range length of (2N+1) consecutive points centered on the wavelength λ _i of interest is assumed, and the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS ( λ), and the root mean square ΔC _RMS (λ _i ) of the difference in the target wavelength range is calculated as the coefficient deviation amount. The wavelength λ _i is varied within the range where the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ) overlap, and the adjacent length N is also varied within a predetermined range. Then, the combination of the wavelength λ _K and the adjacent length N that minimizes the coefficient deviation amount ΔC _RMS (λ _i :N) is determined as the joint wavelength range. That is, the joint wavelength range is determined as a range including N points on each of the short wavelength side and the long wavelength side with the wavelength _λK as the center.

Note that the shift amount of the calibration coefficient at the wavelength λ _i is calculated based on the ratio of the calibration coefficient C _UV (λ) to the calibration coefficient C _VIS ( _λ ). It may be calculated based on the ratio of _VIS (λ), or may be a simple difference between the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ).

In this way, the process of determining the seam wavelength range includes the process of searching for an interval in which the deviation between the values of the calibration coefficients C _UV (λ) and C _VIS (λ) is minimized.

FIG. 14 is a diagram showing an example of processing for determining the joint wavelength range in the optical measurement method according to this embodiment. In the example shown in FIG. 14, the coefficient deviation amount ΔC _RMS (λ _i :N) is calculated for three types of adjacent lengths N=1, 2, and 3 with respect to the wavelength λ _K . In this example, the coefficient deviation amount ΔC _RMS (λ _i :N) takes the minimum value when the adjacency length N=1, so the adjacency length N=1 is determined. Then, an interval including three points centered on the wavelength _λK is determined as the joint wavelength range.

As described above, in the seam wavelength range search process, the coefficient deviation amount ΔC _RMS (λ _i : N) is calculated for each adjacent length N (N=1, 2, . . . ), and the calculated coefficient The minimum value of the shift amounts ΔC _RMS (λ _i :N) is determined. The seam wavelength range is determined based on the wavelength λ _K and the adjacent length N at which the coefficient deviation ΔC _RMS (λ _i :N) takes the minimum value.

The seam wavelength range can be determined by the search processing as described above. Note that the joint wavelength range usually means a range including a plurality of wavelengths, but it may also include a case consisting of only one wavelength. In this case, the intersection of the calibration coefficients C _UV (λ) and C _VIS (λ) typically corresponds to the seam wavelength range.

(f3: Arithmetic processing for connecting calibration coefficients)
Next, a description will be given of arithmetic processing for joining calibration coefficients in the determined joint wavelength range. Arithmetic processing for connecting calibration coefficients corresponds to processing for determining correction values of calibration coefficients for each wavelength included in the joint wavelength range (correction target section for which correction values of calibration coefficients are to be determined).

FIG. 15 is a diagram for explaining the process of connecting calibration coefficients in the optical measurement method according to this embodiment. Referring to FIG. 15, even in the seam wavelength range there is a deviation between the calibration factors C _UV (λ) and C _VIS (λ). That is, at each wavelength, the calibration coefficients C _UV (λ) and C _VIS (λ) do not exactly match.

Therefore, it is preferable to apply some interpolation process to determine the calibration factor for each wavelength. The interpolation process preferably also maintains continuity with the calibration coefficients at adjacent wavelengths as much as possible.

FIG. 16 is a diagram for explaining a processing example of connecting calibration coefficients in the optical measurement method according to this embodiment. Referring to FIG. 16, the calibration coefficient C(λ) is determined by weighting the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ) in accordance with the wavelength in the seam wavelength range.

More specifically, a greater weight is given to the calibration coefficient C _UV (λ) on the shorter wavelength side, while a greater weight is given to the calibration coefficient C _VIS (λ) on the longer wavelength side. The weight to be given may correspond to the distance (wavelength difference) from the wavelength _λK , which is the center wavelength of the joint wavelength range. More specifically, for example, the correction value of the calibration coefficient at the wavelength _λi of the calibration coefficient C(λ) can be determined according to the weighting calculation shown in the following equation (7).

As described above, based on the calibration coefficient C _UV (λ) (first calibration coefficient) and the calibration coefficient C _VIS (λ) (second calibration coefficient), the calibration range (first wavelength range) of the ultraviolet standard bulb 2 and the calibration range (second wavelength range) of the visible standard bulb 4 overlap with each other. More specifically, for the values of the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ) at each wavelength included in the joint wavelength range (correction target section), each A correction value for the corresponding calibration coefficient is determined by giving a weight.

The calibration coefficients C(λ _i ) in the seam wavelength range can be determined by such a computational process of stitching together the calibration coefficients.

(f4: processing procedure)
Next, the process of determining the calibration coefficient C(λ) will be described.

FIG. 17 is a flow chart showing a more detailed processing procedure of step S18 in FIG. Referring to FIG. 17, calibration coefficient C _UV (λ) is calculated (step S181). Similarly, based on the second detection result obtained for the visible standard bulb 4 and the spectral irradiance assigned to the visible standard bulb 4, the calibration coefficient C _VIS (λ) for the visible standard bulb 4 is calculated as follows: Calculate (step S182).

For the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ), a search is made for a combination of the wavelength λ _K and the adjacent length N that minimizes the coefficient deviation amount ΔC _RMS (λ _i :N) (step S183). . Based on the wavelength λ _K and the adjacent length N found in step S183, the seam wavelength range is determined (step S184).

For each wavelength included in the joint wavelength range determined in step S184, a correction value of the calibration coefficient is calculated by weighting operation based on the calibration coefficient C _UV (λ) and the calibration coefficient C _VIS (λ) (step S185 ).

For wavelengths shorter than the seam wavelength range, the calibration coefficient corresponding to the calibration coefficient C _UV (λ) is adopted, and for the seam wavelength range, the correction value of the calibration coefficient calculated in step S185 is adopted, and wavelengths longer than the seam wavelength range are adopted. , the calibration coefficient C(λ) is determined by adopting the calibration coefficient corresponding to the calibration coefficient C _VIS (λ) (step S186).

Note that when the joint wavelength range is set to a range including 400 [nm], the calibration coefficient corresponding to the calibration coefficient C _VIS (λ) may not necessarily be required. Therefore, the calibration factor C(λ) is determined based on at least the calibration factor C _UV (λ) (first calibration factor) and the calibration factor correction value included in the seam wavelength range.

(f5. Synthesis result)
FIG. 18 is a diagram showing an example of calibration coefficients C(λ) synthesized in the optical measurement method according to this embodiment. Referring to FIG. 18, it can be seen that a more accurate calibration coefficient can be determined by synthesizing the calibration coefficient C(λ) from a plurality of calibration coefficients.

<G. Processing device>
A portion of the optical measurement method according to this embodiment may be performed by a processor connected to spectrophotometer 50 .

FIG. 19 is a schematic diagram showing a hardware configuration example of a processing device 100 for realizing the optical measurement method according to this embodiment. 19, processing device 100 includes processor 102, main memory 104, input unit 106, display unit 108, storage 110, communication interface 120, network interface 122, and media drive 124. include.

The processor 102 is typically an arithmetic processing unit such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit), and reads one or more programs stored in the storage 110 to the main memory 104 and executes them. do. The main memory 104 is a volatile memory such as DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory), and functions as a working memory for the processor 102 to execute programs.

Input unit 106 includes a keyboard, a mouse, and the like, and receives operations from the user. The display unit 108 outputs results of program execution by the processor 102 to the user.

The storage 110 is composed of non-volatile memory such as a hard disk and flash memory, and stores various programs and data. More specifically, the storage 110 holds an operating system 112 (OS: Operating System), a measurement program 114 , measurement results 116 and setting parameters 118 .

Operating system 112 provides an environment in which processor 102 executes programs. Measurement program 114 is executed by processor 102 to implement the optical measurement method and the like according to the present embodiment. Measurement results 116 include measurements of the photometric quantity (spectral radiant flux Φ _SMP (λ) or total radiant flux Φ _SMP ) of the sample. The setting parameters 118 include the certified value of the ultraviolet standard bulb 2, the certified value of the visible standard bulb 4, the spectral radiant flux Φ _ST (λ) assigned to the secondary standard bulb 6, and the secondary standard bulb 6 being turned on. It sometimes includes values such as detection results (reference values) output from the spectrophotometer 50 .

Communication interface 120 mediates data transmission between processor 100 and spectrophotometer 50 . Network interface 122 mediates data transmission between processing device 100 and an external server device.

The media drive 124 reads necessary data from a recording medium 126 (such as an optical disc) that stores a program to be executed by the processor 102 and stores it in the storage 110 . Note that the measurement program 114 and the like executed in the processing device 100 may be installed via the recording medium 126 or the like, or may be downloaded from the server device via the network interface 122 or the like.

The measurement program 114 may call necessary modules out of the program modules provided as part of the operating system 112 in a predetermined sequence at predetermined timings to execute processing. In such a case, the technical scope of the present invention also includes the measurement program 114 that does not include the module. The measurement program 114 may be provided as part of another program.

All or part of the functions provided by execution of the measurement program 114 by the processor 102 of the processing device 100 may be implemented by dedicated hardware. Also, part or all of the processing handled by the processing device 100 shown in FIG. 19 may be incorporated into the spectrophotometer 50 .

<H. Variation>
In the above-described embodiments, the spectral radiant flux Φ _SMP (λ) and the total radiant flux Φ _SMP were described as examples of the photometric quantity of the sample. can be done.

In the above-described embodiment, an example of using a combination of an ultraviolet standard bulb and a visible standard bulb having spectral irradiance values is described. may be used in combination with

<I. Summary>
According to the present embodiment, using a national standard traceable spectral irradiance standard bulb (deuterium lamp: ultraviolet standard bulb 2) and a spectral irradiance standard bulb (halogen lamp: visible standard bulb 4), A national standard traceable standard light bulb is provided in which physical quantities other than spectral irradiance are valued simply by valuing the secondary standard light bulb and comparing and measuring the priced secondary standard light bulb with a sample. It is possible to measure the photometric quantity of a sample even in a wavelength range that is not

According to the present embodiment, compared to the method of calibrating the device by placing the spectral irradiance standard bulb outside the integrating sphere as disclosed in Non-Patent Document 4, the overall work process is small, and , no skill is required. Therefore, according to the present embodiment, highly accurate measurement can be realized more easily and in a short time, and necessary calibration can be performed more frequently, so that measurement accuracy can be improved.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

2 standard bulb for ultraviolet, 4 standard bulb for visible, 6 secondary standard bulb, 8 sample, 10 first measurement system, 12 optical bench, 14 support member, 16, 18 base member, 20 second measurement system, 22 goniometer stage , 24 first rotation axis, 26 holding member, 28 second rotation axis, 30 third measurement system, 32 integrator, 34 sample window, 36 photometry window, 37 light shielding plate, 38 correction light source, 50 spectrophotometer, 60 Light receiving head, 62 aperture, 64 diffusion plate, 66 optical axis, 68 fiber, 100 processing unit, 102 processor, 104 main memory, 106 input unit, 108 display unit, 110 storage, 112 operating system, 114 measurement program, 116 measurement result , 118 setting parameter, 120 communication interface, 122 network interface, 124 media drive, 126 recording medium, AX1, AX2 rotation axis.

Claims (8)

A spectrophotometer that turns on a first standard light bulb whose spectral irradiance is rated for a first wavelength range and that is positioned at a position separated from the first standard light bulb by a first distance whose spectral irradiance is rated. obtaining the first detection result output from
A second standard light bulb whose spectral irradiance is rated for a second wavelength range that overlaps at least part of the wavelength range with the first wavelength range is turned on, and is separated from the second standard light bulb by the first distance. obtaining a second detection result output from the spectrophotometer placed at a position;
calculating a first calibration factor based on the first detection result and the spectral irradiance valued for the first standard bulb;
calculating a second calibration factor based on the second detection result and the spectral irradiance valued for the second standard bulb;
calculating correction values of the calibration coefficients for wavelengths in a wavelength range where the first wavelength range and the second wavelength range overlap, based on the first calibration coefficient and the second calibration coefficient;
determining a third calibration factor based on at least the first calibration factor and the correction value;
a step of turning on a third standard light bulb and acquiring a third detection result output from the spectrophotometer arranged at a position separated from the third standard light bulb by a predetermined distance;
and pricing the third standard bulb a photometric quantity based on the third detection result and the third calibration factor. Determining the third calibration factor comprises:
determining a correction target section in which the correction value is to be determined, in the wavelength range in which the first wavelength range and the second wavelength range overlap;
and determining the correction value for each wavelength included in the correction target section. 3. The optical measurement method according to claim 2, wherein the step of determining the correction target section includes searching for a section in which the amount of deviation between the value of the first calibration coefficient and the value of the second calibration coefficient is minimum. . The step of determining the correction value for each wavelength included in the correction target section may include: 4. An optical measurement method according to claim 2 or 3, comprising the step of determining the corresponding correction values by giving respective weights according to . obtaining a first irradiance produced by the third standard bulb;
obtaining a second irradiance produced by any sample;
obtaining the photometric quantity of the sample based on the ratio of the first irradiance and the second irradiance and the photometric quantity priced for the third standard bulb. The optical measurement method according to any one of . the first irradiance is generated on the inner wall of the integrator by causing the light from the third standard bulb to enter the integrator;
6. The optical measurement method according to claim 5, wherein said second irradiance is generated on an inner wall of said integrator by causing light from said sample to enter said integrator. The first wavelength range includes an ultraviolet region,
The optical measurement method according to any one of claims 1 to 6, wherein the second wavelength range includes the visible range. A first calibration factor is calculated based on a first detection result for a first standard light bulb whose spectral irradiance is valued for a first wavelength range and the spectral irradiance valued for the first standard light bulb. wherein the first detection result is obtained by lighting the first standard light bulb and using a spectrophotometer placed at a position separated from the first standard light bulb by a first distance for which the spectral irradiance is evaluated. obtained by
A second detection result for a second standard light bulb in which spectral irradiance is rated for a second wavelength range that overlaps at least part of the wavelength range with the first wavelength range, and the second standard light bulb is rated. means for calculating a second calibration coefficient based on the spectral irradiance and the second detection result, the second standard light bulb is turned on and the position separated from the second standard light bulb by the first distance. obtained using said spectrophotometer placed in
means for calculating, based on the first calibration factor and the second calibration factor, a calibration factor correction value for wavelengths in a wavelength range where the first wavelength range and the second wavelength range overlap;
means for determining a third calibration factor based on at least the first calibration factor and the correction value;
determining a photometric quantity to price the third standard light bulb based on a third detection result and the third calibration factor for the third standard light bulb, wherein the third detection result is the third standard light bulb A processor obtained with the spectrophotometer positioned at a predetermined distance from the bulb.

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