Spectral transmittance tester

Abstract

The invention relates to the technical field of spectrum transmittance testing, and discloses a spectrum transmittance tester, which comprises a light source system used for providing polychromatic light illumination for the whole system; the monochromatic system is used for converting polychromatic light into monochromatic light; the motor system is used for assisting the monochromatic system to operate; the dual-channel comparison system is used for performing a comparison experiment on the measurement data and the reference data; the main control circuit system is used for providing circuit connection for the whole system, and the light source system comprises a light source assembly, a focusing system and a dodging assembly. A more convenient mode is provided for the measurement of the spectrum transmittance through an illumination, reference and detection integrated structure without depending on equipment such as a fiber optic spectrometer, so that the cost is reduced, and the efficiency is improved; the symmetrical optical path design facilitates miniaturization and high integration of the whole instrument; meanwhile, reference and measurement channels are homologous and have the same wavelength and energy, so that the accuracy of reference and measurement is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of spectral transmittance testing, in particular to a spectral transmittance testing instrument. Background Art

[0002] The spectral transmittance tester is an instrument for measuring the spectral transmittance of a sample. Each substance has its own unique spectral transmittance. The measurement of spectral transmittance can realize the accurate analysis of the state properties and is widely used in various material analysis fields. In domestic patents, many related spectral transmittance test similar products are disclosed, all of which are designed based on the illumination-detection loop structure, that is, the sample to be tested is illuminated by the front-end illumination module, and the sample transmission light signal is collected by the back-end detection module. The signal is usually a monochromatic light signal after spectral separation. By comparing the transmission light signal of the reference sample in all single chromatographic segments (the reference sample generally has a standard spectral transmittance), the spectral transmittance of the sample to be tested is calculated.

[0003] Most of the existing spectral transmittance test products use a polychromatic light source to directly illuminate the sample, and use a fiber optic spectrometer at the back end to directly measure the transmitted light signal. The spectral transmittance measurement performance depends on the fiber optic spectrometer, and the detection device of the fiber optic spectrometer is generally a linear array detector or a planar array detector, which is relatively expensive. After searching, the Chinese patent authorization announcement number CN216208558U discloses a full-spectrum transmittance tester, including a chassis, on which an optical path alignment device, a display screen, an integrated circuit board, an integrating sphere and a fiber optic spectrometer, and a standard light source are provided, and the integrating sphere and the fiber optic spectrometer are connected by an optical fiber. The patent document uses a fiber optic spectrometer for testing, resulting in excessively high costs. In addition, there are some spectral transmittance test products that use a monochromator as the illumination light source. Such products are large in size and not easy to miniaturize, and it is difficult to set up a reference channel. After searching, Chinese patent announcement number CN117589426A discloses a spectral transmittance test device for an optical system, which is composed of a monochromatic light source module, an illumination module, a collimation optical module, a reference convergence module, a light intensity detection module, a modulation and demodulation module, and a computer. The equipment involved in the patent document is relatively large in size and has a poor integration. Therefore, the present invention provides a spectral transmittance tester to solve the shortcomings of the prior art. Summary of the invention

[0004] In view of the deficiencies of the prior art, the present invention provides a spectral transmittance tester, which solves the problem in the prior art that the equipment used in the spectral transmittance test is high in cost and too large in size resulting in poor integration.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a spectral transmittance tester, comprising: The light source system is used to provide complex color light illumination for the entire system; Monochromatic system, its function is to convert complex color light into monochromatic light; The motor system is used to assist the operation of the monochrome system; Dual-channel comparison system, which is used to compare the measured data with the reference data; The main control circuit system is used to provide circuit connection for the entire system.

[0006] Preferably, the light source system includes a light source component, a focusing system and a light homogenizing component, the light source component includes a tungsten lamp and a power board, and the output end of the power board is electrically connected to the input end of the tungsten lamp.

[0007] Preferably, the focusing system is used to reflect the light emitted by the tungsten lamp and transmit it to the light homogenizing component. The focusing system uses a concave reflector as a focusing mirror, and the function of the light homogenizing component is to homogenize the incident light.

[0008] Preferably, the monochromatic system includes a slit plate, a lens group and a grating, wherein two slits are provided on the surface of the slit plate, one of the slits is used to allow incident light to penetrate, the lens group is used to convert the incident light into parallel light, the grating is used to receive the parallel light and then discretize it according to the spectrum, the two slits are axially symmetrically arranged about the center of the lens group, and an optical coupler is installed on the outside of the grating.

[0009] Preferably, the motor system comprises a servo motor, and an output end of the servo motor is fixedly connected to the central rotation axis of the grating.

[0010] Preferably, the dual-channel comparison system includes an equally divided beam splitter component, a reference channel detector, a sample to be tested and a measurement channel detector. The equally divided beam splitter component is arranged at the other slit of the slit plate. The equally divided beam splitter component is used to split the light into two parts to act on the reference channel detector and the sample to be tested respectively, and the light passing through the sample to be tested will act on the measurement channel detector.

[0011] Preferably, the main control circuit system comprises a main control board, an input end of the main control board is electrically connected to output ends of the reference channel detector and the measurement channel detector, and an output end of the main control board is electrically connected to an input end of the servo motor.

[0012] A method for using a spectral transmittance tester comprises the following steps: Step 1, supplying power to the tungsten lamp to make it emit light; Step 2: Adjust the light generated in step 1 into parallel light; Step 3, irradiate parallel light onto the grating for spectral discretization; Step 4: Collect and record signals from the reference channel and the measurement channel respectively, and then calculate and obtain the relative sample transmittance.

[0013] Preferably, in step one, a power board is used to power the tungsten lamp, in step two, a lens group is used to convert incident light into parallel light, in step three, the servo motor is started to drive the grating to rotate, and in step three, an optical coupler is used to mark the zero position of the servo motor during the servo motor startup initialization process, and the encoder in the servo motor functions to monitor the position and rotation state of the grating in real time.

[0014] The present invention provides a spectral transmittance tester. It has the following beneficial effects: The present invention provides a more convenient way for spectral transmittance measurement through an integrated structure of illumination, reference and detection, and does not rely on equipment such as a fiber optic spectrometer, thereby reducing costs and improving efficiency. In addition, the symmetrical optical path design facilitates the miniaturization and high integration of the entire instrument. At the same time, the reference and measurement channels are of the same source and have the same wavelength and energy, thereby ensuring the accuracy of reference and measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 is a schematic diagram of a light source system of the present invention; Figure 3 It is a schematic diagram of a monochrome system of the present invention; Figure 4 It is a schematic diagram of the overall system structure of the present invention.

[0016] Among them, 1. light source assembly; 2. focusing system; 3. uniform light assembly; 4. slit; 5. lens group; 6. grating; 7. optical coupler; 8. equally divided light splitting assembly; 9. reference channel detector; 10. sample to be tested; 11. measurement channel detector; 12. main control board; 13. servo motor; 14. tungsten lamp; 15. power board. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Please refer to the attached Figure 1 -Attached Figure 4The embodiment of the present invention provides a spectral transmittance tester, including: a light source system, which provides complex light illumination for the entire system; a monochromatic system, which converts complex light into monochromatic light; a motor system, which assists the operation of the monochromatic system; a dual-channel comparison system, which compares the measured data with the reference data; and a main control circuit system, which provides circuit connection for the entire system.

[0019] The power board 15 serves as the power supply core of the tungsten lamp 14, providing the necessary power support for its stable operation. The output end of the power board 15 is tightly electrically connected to the input end of the tungsten lamp 14, ensuring that the current can be stably and accurately transmitted to the tungsten lamp 14. The tungsten lamp 14 has a relatively stable illumination spectrum curve in the visible infrared band. After the tungsten lamp 14 is powered on, based on its internal heating element and specific light-emitting mechanism, it emits complex light containing multiple wavelengths, providing the initial light source for the entire spectral transmittance tester.

[0020] The focusing system 2 uses a concave reflector as a focusing mirror, and its main function is to collect and reflect the divergent light emitted by the tungsten lamp 14. The unique curved surface structure of the concave reflector can converge the light in a specific direction and transmit it to the light homogenizing component 3. Through precise optical design and installation and debugging, it is ensured that the light emitted from the tungsten lamp 14 can be incident on the light homogenizing component 3 at the best angle and intensity, thereby improving the efficiency of light utilization and the accuracy of subsequent experiments.

[0021] After receiving the light reflected from the focusing system 2, the light homogenization component 3 performs homogenization processing on it. It usually contains a series of optical elements, such as an integrating sphere, a diffuser, etc., which transform the light with uneven intensity distribution into a beam with relatively uniform light intensity distribution over the entire cross section through multiple reflections, refractions, scattering and other optical processes. This homogenized light provides a stable and reliable light source foundation for the subsequent monochromation and measurement process, effectively reducing the measurement error caused by uneven light.

[0022] Two slits are provided on the surface of the slit plate 4 and are designed to be axisymmetric. One of the slits serves as a channel for incident light, allowing the light homogenized by the light homogenizing component 3 to pass through. The two slits are arranged axisymmetrically with respect to the center of the lens group 5. This symmetrical design helps to maintain the symmetry and stability of the light in the subsequent optical path propagation and optical processing process, and provides a structural basis for accurate spectral analysis.

[0023] After the light passes through the incident slit of the slit plate 4, it is irradiated onto the lens group 5. The lens group 5 is composed of a plurality of different types of lenses. Through reasonable combination and arrangement, the incident divergent light is converted into parallel light by using the refraction principle of the lens. These parallel lights have uniform propagation directions and stable optical properties, providing ideal input conditions for the subsequent spectral discrete operation of the grating 6.

[0024] Grating 6 is one of the core components of the monochromatic system, which can receive the parallel light converted by lens group 5 and discretize it according to the spectrum. The surface of grating 6 has a series of fine lines. When parallel light is incident on grating 6, diffraction occurs. Light of different wavelengths is separated in space due to different diffraction angles, realizing the discretization of spectrum. Optical coupler 7 is installed on the outside of grating 6. Optical coupler 7 can mark the zero position of servo motor 13 during the initialization process of servo motor 13. The encoder in servo motor 13 is used to monitor the position and rotation state of grating 6 in real time.

[0025] The output end of the servo motor 13 is fixedly connected to the central axis of the grating 6, and plays a key role in accurately controlling the rotation angle of the grating 6 in the entire system. Through the instructions of the main control circuit system, the servo motor 13 can drive the grating 6 to rotate with extremely high precision and stability. As the grating 6 rotates, the image plane position of the spectrally discrete light emitted from it will change, thereby realizing the selection of monochromatic light of different bands. For example, when it is necessary to measure the spectral transmittance of a specific wavelength range, the main control circuit system will control the servo motor 13 to drive the grating 6 to rotate to the corresponding angle according to the preset program, so that the monochromatic light of the required band can pass through the exit slit and enter the subsequent measurement channel.

[0026] The equally divided spectroscopic component 8 is arranged at another slit of the slit plate 4, and its main function is to evenly divide the light emitted from the slit plate 4 into two parts. The two parts of light have the same light intensity and spectral characteristics, one part directly acts on the reference channel detector 9, and the other part first acts on the sample to be tested 10. The equally divided spectroscopic component 8 usually adopts optical elements such as spectroscopic prisms and semi-transparent and semi-reflective mirrors. Through precise optical coating and angle design, it ensures the uniformity and accuracy of spectroscopic analysis, and provides a reliable data basis for subsequent dual-channel comparative measurements. In addition, the present design is not limited to the form of two channels. More or fewer measurement and reference channels can be designed using this scheme. It only needs to increase or decrease the number of spectroscopic groups and enlarge or reduce the size of the instrument.

[0027] After receiving a portion of the light divided by the equally divided light splitting component 8, the reference channel detector 9 converts the optical signal into an electrical signal and transmits it to the main control board 12. This electrical signal, as a reference signal, represents the original intensity and spectral information of the light without attenuation by the sample to be tested 10. After the other portion of light acts on the sample to be tested 10, the intensity and spectral distribution of the light will change due to the different absorption and scattering characteristics of the sample for light of different wavelengths. The light that passes through the sample to be tested 10 then acts on the measurement channel detector 11, which also converts the optical signal into an electrical signal and transmits it to the main control board 12. The main control board 12 calculates the attenuation degree of the light after passing through the sample to be tested 10 by comparing and analyzing the electrical signals transmitted by the reference channel detector 9 and the measurement channel detector 11, thereby obtaining the spectral transmittance of the sample.

[0028] The main control board 12 is the control core of the entire spectral transmittance tester. Its input end is electrically connected to the output end of the reference channel detector 9 and the measurement channel detector 11, and receives the electrical signals from the two detectors in real time. The main control board 12 integrates complex signal processing circuits and microprocessors, which can process and analyze these electrical signals at high speed and precision. The output end of the main control board 12 is electrically connected to the input end of the servo motor 13, and sends control instructions to the servo motor 13 according to the preset measurement program and real-time measurement data. For example, when scanning monochromatic light of different wavelengths, the main control board 12 will accurately control the rotation speed and angle of the servo motor 13 according to the measurement progress and the required wavelength range, ensuring that monochromatic light of different bands can be accurately selected, and corresponding measurements and data collection are performed. At the same time, the main control board 12 can also monitor and regulate the working state of the entire system, such as controlling the power output of the light source system, adjusting the working parameters of the monochromatic system, etc., to ensure that the entire spectral transmittance tester can operate stably and efficiently.

[0029] Specifically, first, the tungsten lamp 14 is powered by a power board 15. The power board 15 can provide the tungsten lamp 14 with stable power that meets its working requirements, ensuring that the tungsten lamp 14 can continuously and stably emit polychromatic light. This stable luminous state provides a reliable light source basis for subsequent optical measurements and ensures the consistency and stability of light throughout the test process. The polychromatic light emitted by the tungsten lamp 14 then passes through the light homogenization component 3. The role of the light homogenization component 3 is crucial, as it can homogenize the light. Through a series of internal optical elements, such as an integrating sphere, a diffuser, etc., the light undergoes multiple reflections, refractions, and scatterings in the light homogenization component 3, and the light that originally had differences in intensity and distribution is converted into a beam with a relatively uniform light intensity distribution over the entire cross section. This homogenized light plays a key role in improving the subsequent measurement accuracy, because uniform light can avoid measurement errors caused by local light intensity differences, ensuring that in subsequent optical path propagation and analysis, the light of each part can participate in the experiment under the same conditions. The light homogenized by the light homogenization component 3 passes through one of the slits on the slit plate 4. The gap of the slit plate 4 plays a role in limiting the propagation path and range of light, so that the light can enter the subsequent optical system in a specific shape and direction. This precise light selection and guidance helps to ensure the accuracy and stability of subsequent optical processing. Then, the light is irradiated onto the lens group 5. The lens group 5 uses its refraction principle to convert the incident divergent light into parallel light. Parallel light has a uniform propagation direction and stable optical properties, which provides ideal input conditions for the subsequent spectral discretization operation of the grating 6. The incidence of parallel light on the grating 6 can ensure that light of different wavelengths is diffracted on the grating 6 according to the expected rules, thereby achieving accurate spectral discretization. After the light is emitted from the grating 6, it is discretized according to the spectrum. The surface of the grating 6 has a series of fine lines. When parallel light is incident on the grating 6, diffraction occurs. Light of different wavelengths is separated in space due to different diffraction angles, thereby achieving spectral discretization. Since the system adopts a symmetrical design, the discretized light returns approximately along the original path. When the light returns to the image plane position, its monochromatic image has the same shape as the incident slit, and covers the entire image plane according to the spectrum. This phenomenon enables monochromatic lights of different wavelengths to clearly present their respective positions and intensity distributions on the image plane, providing an intuitive and accurate basis for subsequent gating operations. The exit slit selects a portion of the discrete light, and the spectrum of the light passing through is a narrow-band monochromatic light. This gating process is one of the key steps to achieve accurate spectral measurement. By selecting a specific exit slit position, narrow-band monochromatic light in the required wavelength range can be accurately selected. This narrow-band monochromatic light has a single wavelength characteristic and can be used to accurately measure the transmittance of the sample 10 to a specific wavelength of light to be tested. The grating 6 is then driven to rotate by the servo motor 13. The servo motor 13 can drive the grating 6 to rotate with high precision and stability. As the grating 6 rotates, the image plane position of the light emitted from it that is discrete according to the spectrum will change.This change enables monochromatic light of different wavelengths to be gated into the measurement channel in turn. By accurately controlling the rotation angle and speed of the servo motor 13, accurate selection of monochromatic light of different wavelengths can be achieved to meet different measurement requirements. After the gated monochromatic light enters the measurement system, the reference channel and the measurement channel collect and record signals respectively. The signal collected by the reference channel detector 9 represents the original intensity and spectral information of the light before passing through the sample to be tested 10, while the signal collected by the measurement channel detector 11 is the intensity and spectral information of the light after passing through the sample to be tested 10. The two channels collect signals at the same time, and can compare and analyze the changes in light under the same time reference. Then repeat the gate-to-measurement process until all wavelengths are scanned. By repeatedly gated monochromatic light of different wavelengths, and performing measurements and signal acquisition, the spectral transmittance information of the sample to be tested 10 in the entire wavelength range can be obtained. This comprehensive scan can construct a complete spectral transmittance curve, which provides rich data support for in-depth analysis of the optical properties of the sample. Then replace the sample to be tested 10 and repeat the above process. Measure again to obtain the spectral transmittance information of the new sample. The two measurement signals are compared, and the ratio of the two measurement signals is the relative sample transmittance. Through this comparison method, the influence of factors such as light source fluctuations and measurement system errors can be eliminated, and more accurate and reliable sample transmittance data can be obtained, thus providing valuable reference for scientific research, production and other fields.

[0030] Working principle: First, the power board 15 is used to power the tungsten lamp 14. The tungsten lamp 14 will emit complex color light and pass through the light homogenizing component 3 to make the optical fiber uniform, and then pass through one of the slits on the slit plate 4, and then irradiate the lens group 5. After passing through the lens group 5, it becomes parallel light and is incident on the grating 6. The light emitted from the grating 6 is discretized according to the spectrum. Due to the use of a symmetrical system, the discretized light returns approximately along the original path. When it reaches the image plane position, its monochromatic image is the same shape as the incident slit, and covers the entire image plane according to the spectrum. The exit slit selects a part of the discretized light, and the spectrum of the light passing through is a narrow-band monochromatic light. Then, the servo motor 13 drives the grating 6 to rotate, which can change the position of the image plane, thereby selecting monochromatic light of different bands, and then the reference channel and the measurement channel collect and record the signals respectively, and then repeat the selection to measurement process until all wavelengths are scanned, and then the sample 10 to be tested is replaced, and the above process is repeated. The ratio of the two measurement signals is the relative sample transmittance.

[0031] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A spectral transmittance tester, characterized in that: include: The light source system is used to provide complex color light illumination for the entire system; Monochromatic system, its function is to convert complex color light into monochromatic light; The motor system is used to assist the operation of the monochrome system; Dual-channel comparison system, which is used to compare the measured data with the reference data; The main control circuit system is used to provide circuit connection for the entire system.

2. A spectral transmittance tester according to claim 1, characterized in that: The light source system comprises a light source component (1), a focusing system (2) and a light homogenizing component (3); the light source component (1) comprises a tungsten lamp (14) and a power board (15); an output end of the power board (15) is electrically connected to an input end of the tungsten lamp (14).

3. A spectral transmittance tester according to claim 2, characterized in that: The focusing system (2) is used to reflect light emitted by the tungsten lamp (14) and transmit it to the light homogenizing component (3). The focusing system (2) uses a concave reflector as a focusing mirror. The function of the light homogenizing component (3) is to homogenize incident light.

4. A spectral transmittance tester according to claim 3, characterized in that: The monochromatic system comprises a slit plate (4), a lens group (5) and a grating (6); two slits are provided on the surface of the slit plate (4), one of the slits being used to allow incident light to pass through; the lens group (5) being used to convert the incident light into parallel light; the grating (6) being used to receive the parallel light and then discretize it according to a spectrum; the two slits are arranged axially symmetrically about the center of the lens group (5); and an optical coupler (7) is installed on the outer side of the grating (6).

5. A spectral transmittance tester according to claim 4, characterized in that: The motor system comprises a servo motor (13), wherein an output end of the servo motor (13) is fixedly connected to a central rotating shaft of the grating (6).

6. A spectral transmittance tester according to claim 5, characterized in that: The dual-channel comparison system comprises an equally divided light splitting component (8), a reference channel detector (9), a sample to be tested (10) and a measurement channel detector (11); the equally divided light splitting component (8) is arranged at another slit of the slit plate (4); the equally divided light splitting component (8) is used to split light into two parts to act on the reference channel detector (9) and the sample to be tested (10) respectively, and light that passes through the sample to be tested (10) will act on the measurement channel detector (11).

7. A spectral transmittance tester according to claim 6, characterized in that: The main control circuit system comprises a main control board (12), an input end of the main control board (12) being electrically connected to output ends of a reference channel detector (9) and a measurement channel detector (11), and an output end of the main control board (12) being electrically connected to an input end of a servo motor (13).

8. A method for using a spectral transmittance tester, applied to a spectral transmittance tester according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1, supplying power to the tungsten lamp (14) to make it emit light; Step 2: Adjust the light generated in step 1 into parallel light; Step 3, irradiating parallel light onto the grating (6) for spectral discretization; Step 4: Collect and record signals from the reference channel and the measurement channel respectively, and then calculate and obtain the relative sample transmittance.

9. The method for using a spectral transmittance tester according to claim 7, characterized in that: In the step 1, a power supply board (15) is used to power the tungsten lamp (14); in the step 2, a lens group (5) is used to convert incident light into parallel light; in the step 3, a servo motor (13) is started to drive the grating (6) to rotate; in the step 3, an optical coupler (7) is used to mark the zero position of the servo motor (13) during the initialization process of the servo motor (13); and the encoder in the servo motor (13) functions to monitor the position and rotation state of the grating (6) in real time.

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