JP4807856B2 - Sample measuring apparatus and sample measuring method - Google Patents

Description

  The present invention relates to a sample measuring device and a sample measuring method for optically measuring the component concentration of a chemical such as an antifungal agent for wood.

As an optical device for measuring transmitted light used to measure the concentration of a chemical solution, the luminous flux from a halogen lamp is incident on and transmitted through a single flow cell, and the transmitted ultraviolet light is passed through a bandpass filter for ultraviolet light. In some cases, the infrared light after transmission is incident on the infrared detector via a bandpass filter (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 7-12726

  However, in the transmitted light measuring optical device, since the concentration of the chemical solution is measured using two kinds of light beams, the device is easily increased in size as a whole, and the concentration calculation processing after the measurement tends to be complicated. Even if two types of light beams are used, if two band-pass filters are used for each light beam, the apparatus becomes expensive.

  Therefore, an object of the present invention is to provide a low-cost and accurate sample measuring apparatus that is simple and small in size and suitable for transportation, and that is simple in concentration calculation processing after measurement.

  Another object of the present invention is to provide a sample measurement method using the sample measurement apparatus.

  In order to solve the above-mentioned problems, a sample measuring apparatus according to the present invention includes (a) an ultraviolet lamp that generates ultraviolet light, and (b) an ultraviolet transmission cell that allows a light beam from the ultraviolet lamp to pass through in a state in which the sample is accommodated. And (c) a semiconductor light detection element for measurement that detects a light beam that has passed through the ultraviolet light transmitting cell, and (d) an output display that displays a value obtained by quantifying the measurement result corresponding to the detection output of the semiconductor light detection element for measurement. An apparatus; (e) an ultraviolet lamp; a semiconductor light detection element for measurement; and a power source for operating the output display device. Here, “displaying a numerical value” means displaying a numerical value in a digital or analog manner, and includes a display for increasing or decreasing the figure size.

  In the above sample measuring device, the measurement semiconductor photodetection element detects the light beam that has passed through the ultraviolet transmission cell, and the output display device displays the value obtained by quantifying the detection output of the measurement semiconductor photodetection device. When the sample in the cell has absorbance in the ultraviolet region, the sample concentration, that is, the concentration of the object in the sample can be easily determined in relation to the ultraviolet light transmittance.

  In a specific aspect of the present invention, in the sample measurement apparatus, the measurement light path is disposed between the ultraviolet light lamp and the measurement semiconductor light detection element, and is disposed at the rear stage and / or the front stage of the ultraviolet light transmission cell. A bandpass filter having a transmission band in the ultraviolet region is further provided. In this case, the ultraviolet light transmittance can be measured by narrowing the wavelength of the sample in the ultraviolet light transmitting cell to light absorption, and the measurement accuracy of the sample concentration can be increased.

  In another aspect of the present invention, the ultraviolet light lamp is a low-pressure mercury lamp, and the output display device has an amplification characteristic determined in consideration of the light emission characteristic of the low-pressure mercury lamp and the transmission characteristic of the bandpass filter. And an electric measuring instrument for measuring the output voltage or output current of the amplifier circuit. In this case, the low-pressure mercury lamp can be miniaturized for portable use, and the amplifier circuit and the electric measuring instrument enable highly accurate and reproducible concentration measurement by setting the operation state.

  In yet another aspect of the present invention, the ultraviolet light lamp, the ultraviolet light transmitting cell, and the semiconductor light detection element for measurement are fixedly housed and stored, and the portable display unit having the display portion of the output display device provided on the outer wall. The light shielding case is further provided. In this case, the sample measuring device can be easily transported to the destination as a portable unit, and the concentration of the object in the sample existing in various places such as outdoors can be quickly measured.

  In yet another aspect of the present invention, an ultraviolet light emitting diode that emits light at a predetermined ultraviolet wavelength different from the measurement wavelength, and a semiconductor light detection for correction that detects a light beam emitted from the ultraviolet light emitting diode and passing through an ultraviolet transmission cell The output display device displays a value obtained by quantifying the result obtained based on the detection output of the correction semiconductor photodetection element and the detection output of the measurement semiconductor photodetection element as a measurement result. In this case, the output display device can display not only the detection output of each semiconductor photodetection element but also a value obtained by quantifying the detection output of the measurement semiconductor photodetection element corrected by the calculation in the control device, for example. Therefore, even if the sample in the ultraviolet transmission cell has light absorbency or the like at a position different from the measurement wavelength in the ultraviolet region due to the influence of impurities, the sample concentration with high accuracy can be easily determined. Moreover, since correction according to the sample is possible, a more accurate sample concentration can be determined.

  In yet another aspect of the present invention, the optical path for measurement and the optical path for correction between the ultraviolet light emitting diode and the semiconductor light detecting element for correction are optical paths that pass through the ultraviolet light transmitting cell, and the ultraviolet light lamp and the ultraviolet light transmitting element. A light-shielding plate that can be arranged between the cells and between the ultraviolet light-emitting diode and the ultraviolet-transmissive cell is further provided, and the measurement optical path and the correction optical path are switched by the arrangement of the light-shielding plates. In this case, stray light can be prevented by shielding the optical path that is not used for measurement, and the ultraviolet transmittance of the sample can be accurately measured while stabilizing the light beam incident on each optical path.

  In yet another aspect of the present invention, the optical path for measurement and the optical path for correction between the ultraviolet light emitting diode and the semiconductor light detecting element for correction are optical paths that pass through the ultraviolet transmissive cell, and the optical path for measurement and the optical path for correction An optical path switching device for switching the optical path is further provided. In this case, the optical path switching device is used to switch the optical path in accordance with the light beam incident on the ultraviolet ray transmitting cell, and measurement is performed for each of the optical path for measurement and the optical path for correction, thereby stabilizing the light beam incident on each optical path. It is possible to accurately measure the ultraviolet transmittance of the sample.

  In yet another aspect of the present invention, the measurement semiconductor photodetection element is used as a correction semiconductor photodetection element, and the amount of transmitted light from the ultraviolet lamp and the ultraviolet light emitting diode on the measurement optical path and the correction optical path, respectively. Measure the amount of transmitted light. In this case, by using the measurement semiconductor light detection element also as the correction semiconductor light detection element, a measurement value in which the ultraviolet transmittance of the sample is corrected can be obtained by using the detection output of one semiconductor light detection element. it can.

  In yet another aspect of the present invention, the light beams incident on the measurement optical path and the correction optical path are independent of each other, the transmitted light amount of the ultraviolet lamp is measured on the measurement optical path, and the transmitted light amount of the ultraviolet light emitting diode is the correction light. Measured on the road. In this case, for example, by measuring the amount of transmitted light independently on each light-shielded optical path, it is possible to accurately measure the ultraviolet transmittance of the sample while stabilizing the light beam incident on each optical path.

  In yet another aspect of the present invention, the light beam is applied to either the measurement semiconductor light detection element or the correction semiconductor light detection element in accordance with the timing at which the light beam is incident on either the measurement optical path or the correction optical path. A control device for controlling the timing of detection is further provided. In this case, by detecting the light beam according to the timing at which the light beam is incident on each optical path, the light beam can be detected efficiently, and the measurement including the calculation of correction can be automated.

  In yet another aspect of the present invention, the control device measures a value corresponding to the baseline of the detection output of the measurement semiconductor light detection element for the ultraviolet light lamp, based on the detection output of the correction semiconductor light detection element for the ultraviolet light emitting diode. To do. In this case, the change in the baseline of the detection output of the measurement semiconductor photodetection element according to the sample having a different ultraviolet absorbance can be corrected by the detection output of the correction semiconductor photodetection element. Here, since the medium, impurities, and the like of the sample are slightly different depending on the sample to be measured, the ultraviolet light absorbency is slightly different for each sample, and usually appears as a change in the background.

  In yet another aspect of the present invention, the control device performs a conversion process of subtracting the base line from the detection output of the measurement semiconductor light detection element for the ultraviolet lamp, and displays the calculation result on the output display device. In this case, the sample concentration can be determined accurately and easily by automatically correcting the detection output of the measurement semiconductor photodetection element.

  In yet another aspect of the present invention, the ultraviolet light transmitting cell contains a sample of wood fungicide solution, laundry detergent solution, and gasoline, and the output display device has a concentration of the sample in the ultraviolet light transmitting cell. The numerical value reflecting is shown. In this case, the concentration of the wood fungicide in the diluent, the concentration of the laundry detergent in the laundry liquid, or the impurity concentration in gasoline can be determined easily and accurately.

  In order to solve the above problems, a sample measurement method according to the present invention is (a) a sample measurement method for measuring the concentration of a sample accommodated in an ultraviolet transmission cell, and (b) a light flux from an ultraviolet lamp, A main measurement step of detecting a light beam that has passed through the ultraviolet ray transmitting cell and passed through the ultraviolet ray transmitting cell on the measurement optical path between the ultraviolet lamp and the measurement semiconductor light detecting element; and (c) a main measurement optical path. Switch to the correction optical path between the ultraviolet light emitting diode and the semiconductor light detection element for correction, and pass the luminous flux from the ultraviolet light emitting diode generated at a wavelength different from the measurement wavelength to the ultraviolet transmitting cell on the correction optical path. And (d) an output process for displaying the digitized value by correcting the measurement result in the main measurement process with the measurement result in the comparative measurement process. Performing the process.

  In the sample measurement method, the measurement semiconductor light detection element and the correction semiconductor light detection element detect different light fluxes of the light source that have passed through the ultraviolet light transmitting cell in each optical path, and the measurement result in the main measurement process is compared with the comparison measurement process. Corrected according to the measurement results and displays the digitized value, so if the sample in the UV transmitting cell has absorptivity etc. in the specific wavelength range of UV, the sample concentration, that is, the concentration of the object in the sample is converted to the UV light transmittance. It can be easily determined with high accuracy in relation to each other.

[First Embodiment]
FIG. 1 is a block diagram conceptually illustrating the structure of the sample measuring apparatus according to the first embodiment of the present invention.

  This sample measuring device 10 is for measuring the concentration of a target component in a chemical solution CS as a sample, and contains an ultraviolet light source 20 that generates illumination light including ultraviolet light, and a chemical solution as an ultraviolet transmissive cell. The ultraviolet ray transmitting cell 30, the bandpass filter 40 that allows only a specific wavelength component to pass through the light transmitted through the ultraviolet ray transmissive cell 30, the light detection device 50 that detects the light flux that has passed through the bandpass filter 40, and the light detection device 50 An amplification device 60 that amplifies current output and the like as appropriate, and an output display device 70 that visually displays the output of the amplification device 60 are provided. Here, the sample measuring device 10 incorporates a power source such as a battery for driving the ultraviolet light source 20, the light detection device 50, the amplification device 60, and the output display device 70, that is, a power supply device.

  The ultraviolet light source 20 is composed of a small low-pressure mercury lamp 21 that is, for example, an ultraviolet light lamp, and the low-pressure mercury lamp 21 is driven by a power supply device 22 that can be turned on / off to be lit with a required luminance. The ultraviolet light source 20 generates visible light or ultraviolet light in the range of 150 to 450 nm, for example, but in this embodiment, ultraviolet light of 200 to 350 nm is used for concentration measurement. The ultraviolet light is often absorbed by the target component in the chemical solution CS, and can be quantified even if the target component is at a low concentration, thus enabling concentration measurement with relatively high accuracy.

  The ultraviolet transmissive cell 30 is a rectangular cylindrical tube container made of, for example, quartz glass, and is disposed on the measurement optical path PA <b> 1 between the ultraviolet light source 20 and the light detection device 50. The ultraviolet transmissive cell 30 has good transparency to the entire ultraviolet light. The thickness of the space in the ultraviolet light transmitting cell 30 in the direction of the measurement optical path PA1 can be appropriately changed depending on the chemical solution CS, that is, the type and concentration of the measurement target, but in a specific embodiment, for example, about 5 to 30 mm. Specifically, it was set to 14 mm.

  The band-pass filter 40 is made of a dielectric multilayer film that transmits only target ultraviolet light, and is disposed on the measurement optical path PA <b> 1 between the ultraviolet light transmitting cell 30 and the photodetector 50. The transmission wavelength of the bandpass filter 40 can be appropriately changed depending on the type and concentration of the measurement target. For example, when measuring the concentration of the wood fungicide treatment solution, the peak at 269 nm was targeted. The bandpass filter 40 can be changed to one having different transmission characteristics according to the type of the chemical liquid CS accommodated in the ultraviolet transmission cell 30.

  The photodetection device 50 is a measurement photodiode 51 that is configured of, for example, a GaAlP-based semiconductor element and is disposed on the measurement optical path PA1 that has passed through the bandpass filter 40, and has high sensitivity in the ultraviolet region and is incident. The output current increases as the amount of ultraviolet light increases. Note that the sensitivity of the measurement photodiode 51 is, for example, in the wavelength range of 150 to 400 nm.

  The amplifying device 60 includes an amplifying circuit main body 61 and a power supply device 62 that drives the amplifying circuit main body 61. The amplification circuit main body 61 amplifies the detection output of the light detection device 50 with an appropriate gain, and generates an output voltage that increases in accordance with the intensity value of the detection light incident on the measurement photodiode 51.

  The output display device 70 includes an electric measuring instrument main body 71 composed of a display device such as a voltmeter circuit or an LCD, and a power supply device 72 that drives the electric measuring instrument main body 71. The output display device 70 displays the voltage value of the amplified output from the amplifier circuit body 61 on a display (described later) as a numerical value that can be visually recognized by the user.

  2 is an external view of the sample measuring device 10 shown in FIG. 1, FIG. 3 (A) is a side view of the sample measuring device 10 shown in FIG. 2, and FIG. 3 (B) is a sample measuring device 10. FIG.

  As shown in FIG. 2, the sample measuring apparatus 10 is housed in an outer case 11 made of a light-shielding material and having a box-like appearance. The dimensions of the outer case 11 are, for example, about 10 cm × 10 cm × 30 cm. A display 73 that is a display unit of the output display device 70 in FIG. 1 is fixed to one side surface of the outer peripheral wall of the outer case 11 so that the user can check the measurement result. Next to the display 73, a snap switch 81, which is a main power switch, is attached so that the user can start and stop the operation of the sample measuring apparatus 10. The exterior case 11 is a portable light shielding case, and the ultraviolet transmissive cell 30, the band pass filter 40, the light detection device 50, the amplification device 60, and the like are accommodated in an internal space where no external light (ultraviolet rays) is incident. ing. Here, the ultraviolet transmissive cell 30 is fixed to a holder (not shown) in a replaceable manner, and the ultraviolet transmissive cell 30 can be replaced by separating the detachable upper lid 11f.

  As shown in FIGS. 3A and 3B, a support plate 12 extending so as to partition the center is fixed in the outer case 11, and the arc tube 21a is built on the support plate 12. A low-pressure mercury lamp 21 is fixed. The low-pressure mercury lamp 21 is supplied with power from the battery BA1 fixed to the back surface of the support plate 12. A holder 83 for the ultraviolet transmitting cell 30 is also fixed on the support plate 12. Further, a photodiode 51 is fixed on the support plate 12 via a pedestal on the opposite side across the holder 83. A band pass filter 40 is attached to the incident surface side of the measurement photodiode 51. Further, an amplification circuit board 85 corresponding to the amplification circuit body 61 of the amplification device 60 is fixed on the support plate 12. The amplifier circuit board 85 is supplied with power from the battery BA2 fixed to the back surface of the support plate 12.

  FIG. 4 is a diagram for explaining the circuit configuration of the sample measuring apparatus 10 shown in FIG. A switch lead for turning on and off the low-pressure mercury lamp 21, a battery BA2 for supplying power to the electric measuring instrument main body 71, a battery BA2 for supplying power to the amplifier circuit board 85, The output signal terminal of the amplifier circuit board 85 is connected to the first connector CO1. Each terminal of the snap switch 81 and the input terminal and power supply terminal of the electric measuring instrument main body 71 are connected to the second connector CO2. A cable CA is interposed between the first connector CO1 and the second connector CO2, and the corresponding numbers of both the connectors CO1 and CO2 are electrically connected. As a result, when the snap switch 81 is turned on, the power supply voltage is supplied to the low-pressure mercury lamp 21, the amplification circuit board 85, and the electric measuring instrument main body 71, and the power supply is turned on. When the low-pressure mercury lamp 21 is turned on, an ultraviolet transmission cell 30 (not shown) is illuminated with ultraviolet rays. Since the transmitted light of the ultraviolet light transmitting cell 30 enters the measurement photodiode 51 through the bandpass filter 40 (not shown), the detection signal of the measurement photodiode 51 is amplified by the amplification circuit board 85 and is amplified. 85 output signals are input to the electric measuring instrument main body 71 as input signals. The electric measuring instrument main body 71 is a voltmeter and displays a voltage detection value on the display 73.

  FIG. 5 is a diagram for explaining an example of a specific circuit configuration of the amplifier circuit board 85. The amplifier circuit board 85 is formed of an operational amplifier LM358, a capacitor, a fixed resistor, a variable resistor, and the like, and amplifies the detection signal of the measurement photodiode 51 with an appropriate gain and outputs the amplified signal to the electrical measuring instrument main body 71.

  In the sample measuring apparatus 10 described above, the measurement photodiode 51 detects the amount of light transmitted through the sample, and displays the value obtained by quantifying the detected output on the display 73 of the output display device 70. Therefore, the sample in the ultraviolet transmitting cell 30 is displayed. Can absorb the absorbance in the ultraviolet region, the sample concentration, that is, the concentration of the target substance in the sample can be easily determined in relation to the ultraviolet light transmittance. Further, the UV transmittance can be measured by narrowing the sample in the UV transmitting cell 30 to a wavelength having light absorption, and the concentration can be measured with high accuracy and reproducibility by the operation of the amplifier circuit and the electric measuring instrument. Furthermore, the sample measuring apparatus 10 has a built-in power supply and can be easily transported to a destination as a portable unit by downsizing the low-pressure mercury lamp 21 and the like, and samples existing in various places such as outdoors. The concentration of the object inside can be measured quickly.

  Hereinafter, a specific measurement example using the sample measurement apparatus 10 described with reference to FIGS. 1 to 5 will be described.

In the present Example, the density | concentration measurement of the fungicide processing liquid for wood was performed. Nippon Soda Co., Ltd. wood mold preventive agent “Milcut 180 (trademark)” was diluted with water to prepare a dilute solution having a concentration of 0.25 to 2%. 1 mL of this diluent was further dissolved in 50 mL of methanol, and a hydrochloric acid-added sample was obtained. This sample was accommodated in the ultraviolet transmissive cell 30 and measured by the sample measuring apparatus 10 of the present embodiment. Table 1 below shows the relationship between the treatment liquid concentration in the sample that is the dilution liquid and the measurement value that is the display value of the display 73.

  As is clear from Table 1 above, a good correlation was observed between the diluted solution concentration and the measured value, and sufficient reproducibility was observed for the repeated measurement results.

  FIG. 6 is a graph of the results of Table 1, with the horizontal axis representing the measured voltage output and the vertical axis representing the fungicide concentration. As is apparent from the graph, the concentration of the fungicide for wood in the ultraviolet light transmitting cell 30 can be quickly determined from the display value of the display 73 by interpolating or extrapolating the curve in the graph without scanning the measuring light. You can see that it can be decided. In the conventional spectroscopic analyzer or the like, adjustment at startup is complicated and it takes time to stabilize the operation, and simple operation as in this embodiment is impossible.

In this example, the concentration of laundry detergent was measured. A washing detergent “Attack (trademark)” manufactured by Kao Corporation was diluted with water to prepare a diluted solution having a concentration of 50 to 1000 mg / L. The diluted solution was filtered with a fold-fold filter paper to obtain a sample from which insoluble matters were removed. This sample was accommodated in the ultraviolet transmissive cell 30 and measured by the sample measuring apparatus 10 of the present embodiment. Table 2 below shows the relationship between the laundry detergent concentration in the sample that is the diluent and the measured value that is the display value of the display 73.

  As is clear from Table 2 above, a good correlation was observed between the laundry detergent concentration and the measured value, and sufficient reproducibility was observed for the results of repeated measurement.

  FIG. 7 is a graph of the results in Table 2, with the horizontal axis representing the measured voltage output and the vertical axis representing the detergent concentration. As is apparent from the graph, the concentration of the laundry detergent in the ultraviolet light transmitting cell 30 can be quickly determined from the display value of the display 73 by interpolation or extrapolation of the curve in the graph without scanning the measurement light. I understand.

In this example, gasoline BTX concentration was measured. Toluene was added to gasoline, and a diluted solution having a concentration of 50 to 1000 mg / L was prepared to obtain a sample. This sample was accommodated in the ultraviolet transmissive cell 30 and measured by the sample measuring apparatus 10 of the present embodiment. Table 3 below shows the relationship between the toluene concentration in the sample that is the diluent and the measured value that is the display value of the display 73.

  As is clear from Table 3 above, a good correlation was observed between the toluene concentration and the measured value, and sufficient reproducibility was observed for the repeated measurement results.

  FIG. 8 is a graph of the results in Table 3, with the horizontal axis representing the measured voltage output and the vertical axis representing the toluene concentration. As is apparent from the graph, the concentration of toluene in the ultraviolet transmission cell 30 and the concentration of BTX in the ultraviolet transmission cell 30 can be quickly determined from the display value of the display 73 by interpolation or extrapolation of the curve in the graph without scanning the measurement light. You can see that it can be decided.

[Second Embodiment]
Hereinafter, a sample measuring apparatus according to the second embodiment will be described. Note that the sample measurement device 110 according to the second embodiment is a modification of the sample measurement device 10 according to the first embodiment, and parts that are not particularly described are the same as those in the first embodiment.

  FIG. 9 is a diagram for explaining an optical system portion of the sample measuring apparatus 110 according to the second embodiment. FIG. 10 is a diagram for explaining the circuit configuration and the like of the sample measuring apparatus 110. The sample measuring device 110 includes an ultraviolet light source 120, an ultraviolet transmission cell 30, a light detection device 150, a bandpass filter 40, and an optical path switching device 140 as an optical system, and an amplification device 160 as a circuit system. An output converter 170, a voltage generator 91, a controller 92, an input device 93, and a display 94. Here, the output conversion device 170 and the display 94 function as an output display device for displaying the measurement result. The sample measuring device 110 includes an ultraviolet light source 120, a light detection device 150, an optical path switching device 140, an amplification device 160, an output conversion device 170, a voltage generation device 91, a control device 92, an input device 93, A power source for driving the display 94, that is, a power supply device is incorporated.

  The ultraviolet light source 120 includes, for example, a small low-pressure mercury lamp 21 and an ultraviolet light emitting diode 23. The low-pressure mercury lamp 21 is driven by a power supply device 22 that can be turned on / off via a control device 92 and is lit with a required luminance. The low-pressure mercury lamp 21 generates visible light or ultraviolet light in a range of 150 to 450 nm, for example, but in this embodiment, ultraviolet light of 200 to 350 nm is used for concentration measurement. On the other hand, the ultraviolet light emitting diode 23 is driven by a power supply device 22 that can be turned on and off in the same manner, and is lit at a required luminance. The ultraviolet light emitting diode 23 has a maximum peak at 400 nm, for example, but in the present embodiment, ultraviolet light (correction reference light) near 350 nm is used for correction measurement.

  The light detection device 150 receives a light beam from the low-pressure mercury lamp 21 as a measurement light, a measurement photodiode 51 that is a measurement semiconductor light detection element, and a correction light beam that receives a light beam from the ultraviolet light-emitting diode 23 as background light. The correction photodiode 52 is a semiconductor light detection element. Note that the sensitivity of both photodiodes 51 and 52 is, for example, in the range of 150 to 400 nm.

  The band pass filter 40 is disposed on the measurement optical path PA1 between the low-pressure mercury lamp 21 and the measurement photodiode 51. Since the ultraviolet light-emitting diode 23 emits a light beam having a relatively narrow specific wavelength, it is not necessary to provide a band-pass filter on the correction optical path PA2 between the ultraviolet light-emitting diode 23 and the correction photodiode 52. .

  The optical path switching device 140 includes light shielding plates 41 and 42 for shielding light beams from the light sources 21 and 23 incident on the photodiodes 51 and 52, respectively, and light shielding plate holders 43 and 44 for holding the light shielding plates 41 and 42, respectively. And a light shielding plate switching device 45 that slides the light shielding plates 41 and 42 to change the positions of the light shielding plates 41 and 42 in order to open the optical path PA1 or PA2. The light shielding plates 41 and 42 are shielded between the low-pressure mercury lamp 21 and the ultraviolet light transmitting cell 30 and between the ultraviolet light emitting diode 23 and the ultraviolet light transmitting cell 30 when shielding the light paths PA1 and PA2, respectively. Can be placed. Further, the light shielding plates 41 and 42 are also movable to the retracted positions retracted from the optical paths PA1 and PA2. The light shielding plate switching device 45 includes a slide mechanism, an actuator, and the like, and is driven and controlled by the control device 92 including the operation timing.

  The amplification device 160 includes an amplification circuit board 201 that amplifies the output signal of the measurement photodiode 51 and an amplification circuit board 202 that amplifies the output signal of the correction photodiode 52. The amplification circuit boards 201 and 202 amplify the detection output of the light detection device 150 with an appropriate gain, and increase the output voltage according to the intensity value of the detection light incident on the measurement photodiode 51 and the correction photodiode 52. appear.

  The output conversion device 170 includes a pair of A / D converters 171 and 172. The amplification circuit boards 201 and 202 amplify the detection signals of the measurement photodiode 51 and the correction photodiode 52 with appropriate gains and output the amplified signals to the A / D converters 171 and 172, respectively. The A / D converters 171 and 172 convert the detection signal into digital data. The display 94 constitutes an output display device together with the A / D converters 171 and 172. The display 94 is for displaying the measurement result obtained from the converted output by the A / D converters 171 and 172, and displays the voltage value of the amplified output from the amplifying device 160 as a numerical value that can be visually recognized by the user. To do.

  The voltage generator 91 is connected to the amplifier circuit board 201 and adjusts the voltage supplied to the operational amplifier A1 of the amplifier circuit board 201. The voltage generated by the voltage generator 91 is appropriately adjusted depending on the type of sample to be measured.

  The input device 93 receives an operation of a button or the like (not shown) provided on the input device 93 and outputs a command for instructing the control device 92 to start the sample measurement. In addition, by operating the input device 93, parameters of the measurement sample can be set in the control device 92, and output adjustment, calculation correction adjustment, and the like of the voltage generator 91 can be performed according to the sample.

  The control device 92 selects one of the measurement photodiode 51 and the correction photodiode 52 according to the timing at which the light beam is incident on one of the measurement optical path PA1 and the correction optical path PA2 via the light shielding plate switching device 45. The timing for detecting the light beam on one side is controlled. Thereby, data can be taken in at an appropriate timing, and the luminous flux can be detected efficiently.

  Further, if necessary, the control device 92 may be configured to turn on / off the power of the low-pressure mercury lamp 21 and the ultraviolet light-emitting diode 23 via the power supply device 22 in accordance with an instruction from the input device 93. The low-pressure mercury lamp 21 and the ultraviolet light-emitting diode 23 can be manually turned on / off.

  When the low-pressure mercury lamp 21 is turned on and the measurement optical path PA1 is selected by the optical path switching device 140, the ultraviolet transmissive cell 30 (not shown) is illuminated with ultraviolet rays. Since the light transmitted through the ultraviolet light transmitting cell 30 enters the measurement photodiode 51 via the bandpass filter 40, the detection signal of the measurement photodiode 51 is amplified by the amplification circuit board 201 and output from the amplification circuit board 201. The signal is input to the A / D converter 171 as an input signal. Further, when the ultraviolet light emitting diode 23 is turned on and the correction optical path PA2 is selected by the optical path switching device 140, the ultraviolet transmissive cell 30 is illuminated with ultraviolet light. Since the transmitted light of the ultraviolet light transmitting cell 30 is directly incident on the correction photodiode 52, the detection signal of the correction photodiode 52 is amplified by the amplification circuit board 202, and the output signal of the amplification circuit board 202 is converted to A / D. The signal is input to the converter 172 as an input signal. The A / D converters 171 and 172 function in the same manner as the voltmeter to output digital voltage detection values, and the digital voltage detection values obtained by the A / D converters 171 and 172 are sent to the control device 92. .

  Further, the control device 92 determines a value corresponding to the baseline of the detection output of the measurement photodiode 51 for the low-pressure mercury lamp 21 based on the detection output of the correction photodiode 52 for the ultraviolet light-emitting diode 23. After data is sent from the A / D converters 171 and 172, the control device 92 performs a conversion process for subtracting the baseline from the detection output of the measurement photodiode 51 for the low-pressure mercury lamp 21, and the calculation result is displayed on the display 94. Is displayed.

  Hereinafter, the operation mechanism of the optical system portion of the sample measuring apparatus 110 and the sample measuring method will be described. The sample measurement method using the sample measurement device 110 is executed under the control of the control device 92, and includes a main measurement process for measuring the light flux that has passed through the ultraviolet light transmitting cell 30 on the measurement optical path PA1, and the correction optical path PA2. It comprises a comparative measurement process for measuring the light flux that has passed through the ultraviolet transmitting cell 30, and an output processing process for correcting the measurement result in the main measurement process with the measurement result in the comparative measurement process and displaying the digitized value.

  In the main measurement process, as shown in FIG. 9A, the light beam emitted from the low-pressure mercury lamp 21 is adjusted to a specific ultraviolet region by the band-pass filter 40. The light shielding plate 42 is moved to the retracted position by the light shielding plate switching device 45 based on the control signal of the control device 92, and the measurement optical path PA1 is opened. At this time, the correction optical path PA2 is shielded by the light shielding plate 41 at the light shielding position. By opening the measurement optical path PA1, the light beam emitted from the low-pressure mercury lamp 21 passes through the ultraviolet light transmitting cell 30 and enters the measurement photodiode 51. The light beam incident on the measurement photodiode 51 is amplified by the amplifier circuit board 201 of FIG. 10, and an output voltage is generated. This voltage value is sent to the control device 92 as a digital voltage detection value.

  Next, in the comparative measurement step, as shown in FIG. 9B, the light shielding plate 41 is moved to the retracted position by the light shielding plate switching device 45 based on the control signal of the control device 92, and the correction optical path PA2 is opened. Has been. At this time, the measurement optical path PA1 is shielded from light by the light shielding plate 42 at the light shielding position. By opening the correction optical path PA 2, the light beam emitted from the ultraviolet light emitting diode 23 passes through the ultraviolet transmission cell 30 and enters the correction photodiode 52. The light beam incident on the correction photodiode 52 is amplified by the amplifier circuit board 202 of FIG. 10, and an output voltage is generated. This voltage value is sent to the control device 92 as a digital voltage detection value.

Next, in the output processing step, the digital voltage detection value in the main measurement step sent to the control device 92 is corrected by the digital voltage detection value in the comparison measurement step, and the value after the conversion processing corresponds to the concentration of the sample. It is displayed on the display 94 as a value. Specifically, the digital voltage detection value in the main measurement process and the comparative measurement process is converted using the following equation. Note that the values of a, b, and c vary depending on the sample to be measured.
Y = aX ₁ + bX ₂ + c
X ₁ : Amount of light transmitted through the sample by the low-pressure mercury lamp that has passed through the band-pass filter (digital voltage detection value in the main measurement process)
X ₂ : Amount of light transmitted through the sample by the ultraviolet light emitting diode (digital voltage detection value in the comparative measurement process)
Y: Spectrophotometer absorbance (275 to 350 nm) predicted from X ₁ and X ₂ (corrected value)

  In the sample measuring device 110 described above, the control device 92 corrects the transmitted light amount of the sample detected by the measuring photodiode 51 by the transmitted light amount of the sample detected by the correcting photodiode 52, and converts the numerical value into a numerical value. It can be displayed on the display 94. Therefore, even when the sample in the ultraviolet light transmitting cell 30 has light absorbency or the like at a position different from the measurement wavelength in the ultraviolet region due to the influence of impurities, the accurate sample concentration can be easily determined. In addition, since correction is performed according to the sample, a more accurate sample concentration can be determined. In the sample measuring apparatus 110, stray light can be prevented by blocking the optical path not used for measurement by using the optical path switching apparatus 140. Furthermore, by making the light beams incident on the optical paths PA1 and PA2 independent, it is possible to accurately measure the ultraviolet transmittance of the sample while stabilizing the light beams. The corrected value Y does not have to be the absorbance of the spectrophotometer, and the result directly converted to the actual concentration can be displayed.

  Hereinafter, a specific measurement example using the sample measurement apparatus 110 described with reference to FIG. 9 will be described.

  As a method of correcting the measurement value, it is conceivable to correct the influence of the treatment liquid on the measurement value due to coloring or turbidity by subtracting this as a fixed value of the increase in the baseline. For example, when an increase in the baseline is observed compared to the standard sample, it can be dealt with by subtracting the increase at 350 nm from the absorbance at 267 nm based on a highly accurate confirmation test using a spectrophotometer.

  However, depending on the sample, there is a difference in the amount of increase in the baseline between the measurement samples, and it is not possible to subtract the measurement result with this as a constant constant.

  Therefore, in this example, the concentration measurement of the mildew-proof material diluted solution after the wood treatment was performed using the sample measurement device 110 of the second embodiment that corrects the measurement result on the assumption that the baseline is fluctuated.

Table 4 below shows the amount of light transmitted through the sample in the low-pressure mercury lamp 21 that has been transmitted through the band-pass filter to the data obtained by subtracting the 350 nm baseline rise from the absorbance at 275 nm using a spectrophotometer. This is a contrast. In this case, the correlation was low particularly on the low concentration side, as shown in the graph of FIG. It can be seen that the measurement of the low-pressure mercury lamp 21 alone cannot cope with the change in the baseline, and the reliability after the measurement may be lowered.

Table 5 below compares the amount of light transmitted through the sample in the ultraviolet light-emitting diode 23 using the sample measuring device 110 and compares it with the amount of increase in the baseline at the spectrophotometer 350 nm. In this case, the correlation was high as shown in the graph of FIG. It can be seen that the baseline change can be detected by the ultraviolet light emitting diode 23.

Table 6 below compares the predicted value obtained by correcting the transmitted light amount of the sample in the low-pressure mercury lamp 21 in Table 4 with the transmitted light amount of the sample in the ultraviolet light-emitting diode 23 in Table 5 and the measured value of the spectrophotometer. . In this case, the correlation was high as shown in the graph of FIG.

From the above, it can be seen that by correcting the amount of light transmitted through the sample in the low-pressure mercury lamp 21 with the amount of light transmitted through the sample in the ultraviolet light-emitting diode 23, it is possible to obtain a measurement value close to the analysis result by the spectrophotometer. A relatively high accuracy measurement result was obtained even with the instrument. Specifically, the conversion processing formula performed by the control device 92 is as follows.
Y = −0.003887X ₁ + 0.1677X ₂ +2.710

  In the second embodiment described above, the system that enables automatic measurement has been described, but manual measurement is also possible. For example, in the main measurement process, the light shielding plate 42 is removed by hand, the measurement optical path PA1 is opened, the light beam incident on the measurement photodiode 51 is amplified by the amplifier circuit board 201 in FIG. 10, and the output voltage value is measured. . At this time, the correction optical path PA2 is shielded by the light shielding plate 41. Next, in the comparative measurement step, the light shielding plate 41 is removed and opened, the light beam incident on the correction photodiode 52 is amplified by the amplifier circuit board 202, and the output voltage value is measured. At this time, the measurement optical path PA1 is shielded by the light shielding plate. Next, in the output processing step, the output voltage value in the main measurement step is corrected and converted by the output voltage value in the comparative measurement step using a calculator and a conversion table, and the concentration of the sample is based on the corrected value. The value corresponding to is determined.

  In the second embodiment, the corrected value is displayed on the display 94, but the measurement values in the main measurement process and the comparative measurement process may be directly displayed.

[Third Embodiment]
Hereinafter, a sample measuring apparatus according to the third embodiment will be described. Note that the sample measurement apparatus 210 according to the third embodiment is a modification of the sample measurement apparatus 110 according to the second embodiment, and parts that are not particularly described are the same as those in the second embodiment.

  14A and 14B show an optical system portion of the sample measuring apparatus 210 according to the third embodiment. In the sample measuring apparatus 210 according to the third embodiment, the optical paths PA1 and PA2 are switched by moving the ultraviolet transmitting cell 30. The ultraviolet light transmitting cell 30 can be moved on each of the optical paths PA1 and PA2 by the optical path switching device 240. The optical path switching device 240 includes a holder (not shown) that fixes the ultraviolet light transmitting cell 30, an actuator (not shown) that moves the holder, and the like. The actuator moves the holder to a predetermined position on each of the optical paths PA1 and PA2, thereby switching the optical paths PA1 and PA2. Here, the light-shielding plate 143 is attached to the side surface portion where the light beam does not enter the ultraviolet transmitting cell 30. Further, the optical path PA1 for measurement and the optical path PA2 for correction are partitioned by a light shielding plate 143, and the ultraviolet light transmitting cell 30 moves completely above either one of the optical paths PA1 and PA2, so that the optical paths PA1 and PA2 are completely obtained. Maintaining independence. Further, the low pressure mercury lamp 21, the ultraviolet light emitting diode 23, the measurement photodiode 51, and the correction photodiode 52 are fixed.

  As shown in FIGS. 14C and 14D, an optical path switching device 241 having a rotation mechanism is provided on the optical paths PA1 and PA2 below the ultraviolet transmitting cell 30, and the ultraviolet transmitting cell 30 is rotated by ± 90 °. Accordingly, the optical paths PA1 and PA2 may be switched. Similar to the optical path switching device 240, the optical path switching device 241 is also composed of a holder for fixing the ultraviolet transmitting cell 30, an actuator, and the like.

  In the sample measuring apparatus 210 described above, correction is performed according to the sample, so that a more accurate sample concentration can be determined. In the sample measurement apparatus 210, stray light can be prevented by blocking the optical path that is not used for measurement by using the optical path switching devices 240 and 241. Furthermore, by making the light beams incident on the optical paths PA1 and PA2 independent, it is possible to accurately measure the ultraviolet transmittance of the sample while stabilizing the light beams.

[Fourth Embodiment]
Hereinafter, a sample measuring apparatus according to the fourth embodiment will be described. Note that the sample measurement device 310 according to the fourth embodiment is a modification of the sample measurement device 110 according to the second embodiment, and parts that are not particularly described are the same as those of the second embodiment. .

  FIGS. 15A and 15B show an optical system portion of the sample measuring apparatus 310 according to the fourth embodiment. In the sample measurement apparatus 310 according to the fourth embodiment, the measurement photodiode 51 is also used as a correction photodiode, and switches the optical paths PA1 and PA2 by moving the low-pressure mercury lamp 21 and the ultraviolet light-emitting diode 23 together. Is done. For example, the optical paths PA1 and PA2 are switched by an optical path switching device 340 provided below the low-pressure mercury lamp 21 and the ultraviolet light-emitting diode 23. The optical path switching device 340 includes a support base 341 and an actuator (not shown). A low-pressure mercury lamp 21, a band pass filter 40, an ultraviolet light emitting diode 23, and a light shielding plate 243 are fixed to the support base 341. The light shielding plate 243 is fixed between the low pressure mercury lamp 21 and the ultraviolet light emitting diode 23. The support base 341 is moved by an actuator, and the optical paths PA1 and PA2 are switched by moving the low-pressure mercury lamp 21 and the ultraviolet light-emitting diode 23 to positions where they enter the measurement photodiode 51, respectively. Here, the ultraviolet transmissive cell 30 and the measurement photodiode 51 are fixed.

  As shown in FIGS. 15C and 15D, an optical path switching device 342 having a rotation mechanism may be provided on the optical paths PA1 and PA2, and the optical paths PA1 and PA2 may be switched. A reflection mirror 244 is fixed on the optical path switching device 342, and one of the optical paths PA1 and PA2 is guided to the measurement photodiode 51 and the other is shielded. The optical paths PA1 and PA2 can be switched by rotating the optical path switching device 342 by ± 90 °.

  In the sample measurement apparatus 310 described above, the measurement value can be corrected with one photodiode by using the measurement photodiode 51 as the correction photodiode 52. Therefore, the cost of the sample measuring device 310 can be reduced. In addition, since correction is performed according to the sample, a more accurate sample concentration can be determined. In the sample measuring device 310, stray light can be prevented by blocking light paths not used for measurement by using the optical path switching devices 340 and 342. Furthermore, by making the light beams incident on the optical paths PA1 and PA2 independent, it is possible to accurately measure the ultraviolet transmittance of the sample while stabilizing the light beams.

  Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments. For example, in the above embodiment, the low-pressure mercury lamp 21 and the ultraviolet light emitting diode 23 are used as the ultraviolet light source 20, but other light emitting tube type ultraviolet light sources can be used, or light emitting diodes that emit near-ultraviolet light, etc. One or more UV lamps in a broad sense can be prepared and turned on simultaneously or individually to emit the desired UV light.

  The ultraviolet light transmitting cell 30 can be formed of a material other than quartz glass as long as the chemical liquid CS can be held and the ultraviolet light can be efficiently transmitted. In particular, when the ultraviolet light transmitting cell 30 is replaced with a resin cell, the resin cell can be made disposable.

  The bandpass filter 40 is not limited to a dielectric multilayer film, and various filters can be used. The band-pass filter 40 is not limited to the rear stage of the ultraviolet transmitting cell 30 but can be disposed in front of the ultraviolet transmitting cell 30, and two band pass filters 40 having slightly different characteristics are arranged before and after the ultraviolet transmitting cell 30. You can also

  Further, the photodetecting device 50 is not limited to the photodiodes 51 and 52 but can be formed by various semiconductor photodetecting elements, that is, solid elements, thereby achieving miniaturization.

  In addition, the amplification device 60, the output display device 70, and the output conversion device 170 are also examples described in the embodiment, and amplify either current or voltage according to a measurement target, and determine either current value or voltage value. You can choose whether to display it properly. Any substance that can be measured can be used as long as it has a property of absorbing ultraviolet light, and can be applied to other fields.

  Further, although the voltage generator 91 is used in the amplifier circuit board 201, the voltage amplification may be adjusted by providing an ND filter corresponding to each sample on the measurement optical path PA1.

  Further, in FIG. 10, the amplifier circuit boards 201 and 202 are provided in the amplifier 160 for each of the photodiodes 51 and 52. However, the amplifier circuit board is integrated into one as the amplifier circuit board 203 of the amplifier 260 in FIG. May be.

  In the present embodiment, the measurement optical path PA1 and the correction optical path PA2 are switched by the optical path switching device 140 or the like, but the optical path may be switched manually.

  In the present embodiment, the sample measuring apparatuses 10 and 110 have built-in power supplies for driving the ultraviolet light sources 20 and 120, but the power may be supplied from the outside.

It is a block diagram which illustrates notionally the sample measuring device concerning a 1st embodiment. It is a perspective view explaining the external appearance of the sample measuring apparatus of FIG. (A), (B) is the side view and top view explaining the inside of the sample measuring device of FIG. It is a block diagram explaining the circuit structure of a sample measuring device. It is a circuit diagram explaining an example of the concrete circuit structure of an amplifier circuit board. It is a graph explaining the measurement result of Example 1 using the sample measuring apparatus shown in FIG. It is a graph explaining the measurement result of Example 2 using the sample measuring apparatus shown in FIG. It is a graph explaining the measurement result of Example 3 using the sample measuring apparatus shown in FIG. It is a block diagram explaining the optical system part of the sample measuring device which concerns on 2nd Embodiment. It is a figure explaining the circuit structure etc. of the sample measuring apparatus of FIG. It is a graph explaining the measurement result of Example 4 using the sample measuring apparatus shown in FIG. It is a graph explaining the measurement result of Example 4 using the sample measuring apparatus shown in FIG. It is a graph explaining the measurement result of Example 4 using the sample measuring apparatus shown in FIG. It is a block diagram explaining the optical system part of the sample measuring device which concerns on 3rd Embodiment. It is a block diagram explaining the optical system part of the sample measuring device which concerns on 4th Embodiment. It is a figure which shows the modification of circuit configurations etc. of the sample measuring device of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10,110,210,310 ... Sample measuring device, 11 ... Exterior case, 12 ... Support plate, 20, 120 ... Ultraviolet light source, 21 ... Low pressure mercury lamp, 22, 62, 72 ... Power supply device, 23 ... Ultraviolet light emitting diode 30 ... UV transmitting cell, 40 ... Bandpass filter, 41, 42, 143, 243 ... Light shielding plate, 50,150 ... Photodetection device, 51,52 ... Photodiode, 60,160,260 ... Amplification device, 61 ... Amplifying circuit main body, 70 ... output display device, 71 ... electric measuring instrument main body, 73, 94 ... display, 81 ... snap switch, 85, 201, 202, 203 ... amplifying circuit board, 92 ... control device, 140, 240, 241 340, 342 ... Optical path switching device, 170 ... Output converter, 171, 172, 173 ... A / D converter BA1, BA2, BA3 ... battery, PA1 ... measuring optical path, PA2 ... correction optical path, SC ... chemical

Claims (12)

An ultraviolet lamp that generates ultraviolet light;
An ultraviolet transmissive cell for passing a light beam from the ultraviolet light lamp in a state in which a sample is accommodated;
A semiconductor photodetection element for measurement for detecting a light beam that has passed through the ultraviolet ray transmitting cell;
An ultraviolet light emitting diode that emits light at a predetermined ultraviolet wavelength range different from the measurement wavelength;
A correcting semiconductor light detecting element for detecting a light beam emitted from the ultraviolet light emitting diode and passed through the ultraviolet light transmitting cell;
An output display device for displaying the value obtained by correcting the measurement result by the semiconductor light detection element for correction with the measurement result by the semiconductor light detection element for measurement and digitizing the measurement result ;
A power source for operating the ultraviolet light lamp, the semiconductor light detecting element for measurement, the ultraviolet light emitting diode, the semiconductor light detecting element for correction, and the output display device ;
The optical path for measurement between the ultraviolet light lamp and the semiconductor light detecting element for measurement, and the optical path for correction between the ultraviolet light emitting diode and the semiconductor light detecting element for correction are optical paths that pass through the ultraviolet light transmitting cell. Because
An optical path switching device for switching between the measurement optical path and the correction optical path, and a detection output of the semiconductor light detection element for measurement with respect to the ultraviolet light lamp by a detection output of the semiconductor light detection element for correction with respect to the ultraviolet light emitting diode And a control device that calculates a value corresponding to the baseline of the sample measurement device. The sample measurement apparatus according to claim 1, further comprising a bandpass filter disposed on the measurement optical path, downstream and / or upstream of the ultraviolet transmission cell and having a transmission band in the ultraviolet region. The ultraviolet lamp is a low-pressure mercury lamp, and the output display device has an amplification circuit having an amplification characteristic determined in consideration of light emission characteristics of the low-pressure mercury lamp and transmission characteristics of the bandpass filter, and the amplification The sample measuring apparatus according to claim 2 , further comprising an electric measuring instrument that measures an output voltage or an output current of the circuit.   The ultraviolet light lamp, the ultraviolet light transmitting cell, and the semiconductor light detection element for measurement are fixedly housed, and a portable light shielding case having a display portion of the output display device provided on an outer wall is further provided. The sample measuring device according to any one of claims 1 to 3, further comprising: Between the UV transmission cell and the ultraviolet lamp, and further comprising a light shielding plate that can be located in the light blocking position between the ultraviolet light emitting diode and the ultraviolet permeation cell,
The sample measuring apparatus according to any one of claims 1 to 4, wherein the measurement optical path and the correction optical path are switched by the arrangement of the light shielding plate.   The sample measurement according to any one of claims 1 to 5, wherein the measurement semiconductor light detection element is provided separately from the correction semiconductor light detection element or is also used as the correction semiconductor light detection element. apparatus. The measurement semiconductor light detection element is used as the correction semiconductor light detection element, and the amount of light transmitted from the ultraviolet lamp and the amount of light transmitted from the ultraviolet light-emitting diode on the measurement optical path and the correction optical path, respectively. The sample measurement device according to claim 6 , wherein the sample is measured. The light beams incident on the measurement optical path and the correction optical path are independent of each other, the transmitted light amount of the ultraviolet lamp is measured on the measurement optical path, and the transmitted light amount of the ultraviolet light emitting diode is measured on the correction optical path. The sample measurement device according to claim 6 . The control device applies a light beam to one of the measurement semiconductor light detection element and the correction semiconductor light detection element according to a timing at which the light beam is incident on one of the measurement light path and the correction light path. The sample measuring device according to claim 1 , wherein the timing for detection is controlled. The said control apparatus performs the conversion process which subtracts the said base line from the detection output of the said semiconductor light detection element for a measurement with respect to the said ultraviolet light lamp, and displays the calculation result on the said output display apparatus from Claim 1 to Claim 9 The sample measuring device according to any one of the preceding claims. The ultraviolet light transmitting cell accommodates a sample of wood fungicide solution, laundry detergent solution, and gasoline, and the output display device shows a numerical value reflecting the concentration of the sample in the ultraviolet light transmitting cell. The sample measuring device according to any one of claims 1 to 10 . A sample measurement method for measuring the concentration of a sample contained in an ultraviolet transmission cell,
Main measurement for detecting the light beam that has passed through the ultraviolet light transmitting cell by passing the light beam from the ultraviolet light lamp through the ultraviolet light transmitting cell on the measurement optical path between the ultraviolet light lamp and the semiconductor light detecting element for measurement. Process,
The optical path for measurement is switched to an optical path for correction between the ultraviolet light emitting diode and the semiconductor light detecting element for correction by an optical path switching device, and the luminous flux from the ultraviolet light emitting diode that emits light at a wavelength different from the wavelength for measurement, A comparative measurement step of passing the ultraviolet light transmitting cell on the optical path for correction through the ultraviolet light transmitting cell and detecting the light beam passing through the ultraviolet light transmitting cell by the semiconductor light detecting element for correction ;
The main measuring the measurement results in step corrected by the measurement result in the comparison measurement process, have rows and output processing step, the displaying the digitized values,
A sample measurement method for calculating a value corresponding to a baseline of a detection output of the measurement semiconductor light detection element for the ultraviolet light lamp based on a detection output of the correction semiconductor light detection element for the ultraviolet light emitting diode .

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