JP3018380U - Photoelectric photometer - Google Patents

Abstract

(57) [Summary] [Purpose] Perform highly accurate sample analysis using a commercially available absorption cell. [Constitution] An absorption cell 3 containing a sample is arranged in an optical path between a light source section 1 and a wavelength selection section 2 and a photometric section 5, and a photoabsorption effect of the sample is measured by the photometric section 5. In the photometer, one reflecting mirror 4a is installed for approaching the first exit of the light from the absorption cell 3 and reflecting the light and returning it back into the absorption cell 3. The light is transmitted through the sample through the folding optical path by the reflecting mirror 4a, so that the transmission distance of the light to the sample is at least twice the length of the sample in the light transmission direction.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to improvement of an optical system of a photoelectric photometer including a colorimeter, a turbidimeter, a colorimeter, and the like.

[0002]

[Prior art]

 A photoelectric photometric analyzer using the absorptiometric analysis (JISK0115) method generally has a sample tank (called an absorption cell) containing a liquid or gas as a measurement sample between the light source section and the wavelength selection section and the photometry section. It is arranged to electrically measure the light absorption effect of the measurement sample.

In the conventional device, the entrance and the exit of the light transmitted through the absorption cell face each other, and therefore, the optical axis for measurement is set so as to substantially overlap with the longitudinal centerline of the absorption cell. Then, the measurement light emitted from the light source section passes through the absorption cell only once and reaches the detector of the photometry section.

[0004]

[Problems to be solved by the device]

 The measurement effect of a photometer is proportional to the distance that light passes through a liquid or gas of a sample (Beer-Lambert's law). Therefore, in the optical system of the conventional photoelectric spectrophotometer, the light inlet and the light outlet of the absorption cell are directly opposed to each other.Therefore, when using a commercially available ordinary absorption cell, depending on the nature of the sample to be measured. The light transmission distance may be too short and the accuracy of sample analysis may be insufficient.

An object of the present invention is to solve the above-mentioned problems and provide a photoelectric photometer capable of highly accurate sample analysis while using a commercially available absorption cell.

[0006]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention arranges an absorption cell containing a sample in an optical path between a light source section, a wavelength selection section and a photometry section, and measures the light absorption effect of the sample by the photometry section. In the photoelectric photometer designed to measure, one reflective mirror was installed to approach the first exit of the light from the absorption cell, reflect the light and return it back into the absorption cell. The absorption cell containing the sample is placed in the light path between the light source section and the wavelength selection section and the photometry section, and the light absorption effect of the sample is measured by the photometry section. In the photoelectric photometer, the incident optical axis from the light source unit to the absorption cell and the emission optical axis from the absorption cell to the photometric unit are shifted from the front-to-back position, and the incident optical axis between the incident optical axis and the emission optical axis is shifted. In order to make the optical path turn back, a plurality of reflecting mirrors are provided in the absorption cell. Ru der which is characterized in that installed in the metering section side and the light source portion side.

[0007]

[Action]

 In the present invention, the light passes through the sample in the absorption cell in the return optical path by the reflection mirror, and the transmission distance of the light to the sample becomes more than twice the length of the sample in the light transmission direction.

[0008]

【Example】

 FIG. 1 is a side view showing an optical system of a photoelectric photometer, which is an embodiment of the present invention, and FIG. 2 is a top view showing the optical system of the photoelectric photometer.

In order to optically shield the optical system from outside light, the entire optical system is housed in a case, but the housing structure of the optical system is omitted in FIGS. 1 and 2.

As the light source 1, a tungsten lamp, a halogen lamp, a deuterium discharge tube, a low pressure mercury lamp, a xenon lamp, a high-intensity LED, a laser, etc. are selected and used according to the sample to be measured.

The wavelength selector 2 is generally composed of an optical filter such as a colored glass filter, a gelatin filter, an interference filter, a metal filter, a non-metal filter, or a monochromator, and selects from the continuous light emitted from the light source 1. Extract only light of a specific wavelength.

The absorption cell 3 is a container that holds a measurement sample or a control sample and is fixed by a holding member (not shown). The absorption cell 3 has high transmittance within the measurement wavelength range and does not penetrate the measurement sample. Although it is made of a material that is not processed and is generally used as a prismatic cell, a cylindrical cell, a microcell, a flow cell, etc., a commercially available prismatic cell as shown in FIG. 3 is shown here as an example. The arrow in FIG. 3 indicates the light transmission direction.

The reflecting mirrors 4 a and 4 b are installed as a pair by two holding members 4 c and 4 d so that the folded optical paths are located on the same horizontal plane before and after the absorption cell 3. 1 and 2, the pair of two reflecting mirrors 4a and 4b is used, but only one reflecting mirror 4a may be used (in this case, the photometric unit is the light source unit side). It is also possible to install three or more reflecting mirrors.

The light receiving element 5 is a photodetector using a photomultiplier tube, a photocell, a photoconductive cell, a photodiode, a phototube, or the like. The shield tubes 6 and 7 are provided to shield the optical path from external light.

In FIG. 1 and FIG. 2, a thin light flux L 2 of about 2 mmφ emitted from the light source 1 passes through the wavelength selector 2 into light having a predetermined wavelength, and passes through the absorption cell 3. The light flux L that has once passed through the absorption cell 3 is reflected in the original direction by the reflecting mirror 4a with its optical axis slightly deviated on the same horizontal plane, passes through the absorption cell 3 again, and is reflected on the same horizontal plane by the reflection mirror 4b. The light is reflected while being kept, is transmitted through the absorption cell 3, and is incident on the light receiving element 5.

As described above, by using a pair of two reflecting mirrors 4a and 4b, the optical path becomes a return optical path, and the conventional photoelectric photometer in which the light source 1 which is the light source section and the light receiving element 5 which is the photometric section face each other. As compared with the measurement system of No. 3, it is possible to obtain a transmission distance more than twice, and therefore, for example, using a commercially available absorption cell 3 having an inner diameter of 10 × 10 × 40 mm as shown in FIG. The measurement sample S enables highly accurate sample analysis.

[0017]

[Effect of device]

 As described above, according to the present invention, light is transmitted through the sample in the absorption cell through the reflection optical path by the reflection mirror, so that the transmission distance of the light to the sample is twice the length in the light transmission direction of the sample. Because of the above, highly accurate sample analysis can be performed while using a commercially available absorption cell.

[Brief description of drawings]

FIG. 1 is a side view showing an optical system of a photoelectric photometer, which is an embodiment of the present invention.

FIG. 2 is a top view showing an optical system of the photoelectric photometer.

FIG. 3 is an external view showing a commercially available prismatic absorption cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 light source 2 wavelength selector 3 absorption cell (sample tank) 4a, 4b reflecting mirrors 4c, 4d holding member 5 light receiving element 6, 7 shielding tube L luminous flux S measurement sample

Claims (3)

[Scope of utility model registration request] 1. A photoelectric photometer in which an absorption cell containing a sample is arranged in an optical path between a light source section, a wavelength selection section, and a photometry section, and the light absorption effect of the sample is measured by the photometry section. , Approaching the first exit of light from the absorption cell,
A photoelectric photometer, comprising one reflecting mirror for reflecting the light and returning it to the absorption cell again. 2. A photoelectric photometer in which an absorption cell containing a sample is arranged in an optical path between a light source section and a wavelength selection section and a photometry section, and the light absorption effect of the sample is measured by the photometry section. An incident optical axis from the light source unit to the absorption cell and an emission optical axis from the absorption cell to the photometric unit are displaced from a facing position, and an optical path between the incident optical axis and the emission optical axis is folded back. In order to achieve the above, a plurality of reflecting mirrors are installed on the photometric section side and the light source section side of the absorption cell, respectively. 3. The photoelectric photometer according to claim 1, wherein the folding optical paths are located on the same horizontal plane.