JPS628507Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photometric section of a photometric device such as a spectrophotometer.

When measuring the reflected light of an opaque sample or the diffused transmitted light of a translucent sample using a spectrophotometer, an integrating sphere is usually used in the photometry section. Conventionally, in this type of photometry section, a photoelectric detector is placed directly at the exit of the integrating sphere, so if the sample absorbs monochromatic light and generates fluorescence, this fluorescence can also be detected at the same time. Therefore, there was a drawback that the true spectrum of the sample could not be measured.

It has also been proposed to remove interference components of light from the sample by interposing a second spectrometer between the sample and the photoelectric detector, but this configuration requires two spectrometers and is expensive. There is a drawback.

This idea was proposed in consideration of this point.
In a device that irradiates a sample with monochromatic light from a spectrometer and photoelectrically converts the light from the sample to measure the reflection or transmission spectrum of the sample, an interference filter is installed in the optical path of the light from the sample to the photoelectric detector. At the same time, the filter is configured by a continuously variable wavelength filter or a plurality of filters having discretely different center wavelengths,
The wavelength switching of the variable wavelength filter or the replacement of the plurality of filters is performed in conjunction with wavelength scanning of the spectroscope.

If the sample does not require wavelength scanning, it is sufficient to use an ordinary fluorescence removal filter as an interference filter, but if wavelength scanning is to be performed, a variable filter is used and the wavelength switching of the filter can be done using the wavelength drive of the spectrometer. Make them interlock.

If the sample is opaque, the filter must be placed between the exit of the integrating sphere and the detector, but if the sample is transparent or translucent, the filter may be placed between the sample holder (cell) and the entrance of the integrating sphere. can.

The illustrated embodiment will be described in detail below.

In the figure, 1 is a spectroscope, 2 is its dispersive element, and 3
4 is an exit slit, 4 is a sample chamber, and 5 is a sample holder or cell in which a transparent or translucent sample is accommodated. Reference numeral 6 denotes an integrating sphere, and a sample cell 5 is arranged at its entrance 7. 8 is a detector such as a photomultiplier tube, which is disposed opposite to the exit 9 of the integrating sphere 6. 10 is
According to the present invention, an interference filter interposed between the exit 9 of the integrating sphere 6 and the detector 8 is used, which in the illustrated embodiment is circular and of variable wavelength type. A filter 10 is supported by a rotating shaft 11 for wavelength selection, and is connected to a gear transmission mechanism 12 and a belt pulley transmission mechanism 1.
3 to the wavelength drive shaft 14. 1
Reference numeral 5 denotes a wavelength drive handle, and by turning it, the wavelength of the spectrometer is driven, and the transmission mechanism 1
3 and 12 to select the wavelength of the filter 10. That is, the dispersive element 2 is controlled by the handle 15.
The pulley diameter and gears are selected so that when the filter 10 is driven by a predetermined wavelength range, the filter 10 also rotates by the same wavelength range.

17 is a standard white plate or an opaque sample; if the sample is transparent, the white plate is placed; if the sample is opaque, the sample is placed. In the latter case the sample cell 5 is removed.

Now, the wavelength λo that comes out of the spectrometer and enters the sample is
When the intensity of monochromatic light is Iλo, the transmitted or reflected light from the sample has a component I′λ with the same wavelength as the incident light.
o and the fluorescence component IF(λ) emitted from the sample, the transmittance or reflectance of the sample is I'λo+ΣIF(λ)/Iλo, which is measured to be larger than the actual value.

However, in the present invention, the filter 10 is linked to the wavelength drive of the spectrometer, so that the wavelength of the output light from the spectrometer is λo.
In this case, the wavelength of the filter 10 is also set to λo, so that λo of the fluorescent component IF(λ) from the sample
It cuts out everything else except nearby ingredients. Therefore, a value close to the correct transmittance or reflectance I'λo/Iλo can be obtained.

In the illustrated embodiment, the interference filter is wavelength tunable and disk-shaped, but a linear wavelength tunable filter may also be used using a rack and pinion as the interlocking coupling mechanism. Furthermore, if it is not necessary to change the wavelength continuously, a plurality of interference filters having discrete center wavelengths may be used.
Even in this case, the wavelength drive of the spectroscope and the selection of a plurality of interference filters can be linked.

In the illustrated embodiment, the interference filter is placed between the outlet 9 of the integrating sphere and the detector 8, but if the sample is transparent or translucent, it may be interposed between the sample holder 5 and the inlet 7 of the integrating sphere. You can.

As described above, according to the present invention, when measuring the diffuse transmission or reflection spectrum of a sample using an integrating sphere, it is possible to eliminate the influence of fluorescence from the sample and obtain a spectrum close to the true spectrum. Furthermore, since the wavelength switching of the filter can be performed in conjunction with the wavelength drive of the spectrometer, the operation is simple and easy.

Note that the present invention can also be applied to ordinary absorption/transmission measurements that do not use an integrating sphere. That is, the sample is irradiated with light from a spectroscope, the filter is interposed between the sample and the detector, and the filter removes the fluorescent component from the light transmitted from the sample and introduces it into the detector. You can also.

[Brief explanation of the drawing]

The figure is a schematic configuration diagram of an embodiment of the present invention. 1... Spectrometer, 5... Sample holder (cell),
6... Integrating sphere, 10... Interference filter, 13...
...Belt/pulley transmission mechanism, 14...Wavelength drive axis, 17...Standard white plate or opaque sample.

Claims (1)

[Scope of utility model registration request] In a device that irradiates a sample with monochromatic light from a spectrometer and photoelectrically converts the light from the sample to measure the reflection or transmission spectrum of the sample, an interference filter is installed in the optical path of the light from the sample to the photoelectric detector. At the same time, the filter is configured by a continuously variable wavelength filter or a plurality of filters having discretely different center wavelengths, and the wavelength switching of the wavelength variable filter or the replacement of the plurality of filters is performed in the spectrometer. A photometric unit of a photometric device, characterized in that the photometric unit performs the measurement in conjunction with wavelength scanning.