Integrating sphere for measuring absorption spectrum and measuring method thereof

Abstract

The application discloses an integrating sphere for measuring absorption spectrum and a measuring method thereof, wherein the integrating sphere comprises a spherical shell, a sapphire carrier, a light source and a fiber probe; the spherical shell has an inner cavity; the sapphire carrier is arranged in the inner cavity and used for carrying an object to be detected; the light source is installed on the spherical shell and used for projecting light to the object to be detected; and the fiber probe is installed on the spherical shell and used for receiving light reflected directly or indirectly from the object to be detected. The integrating sphere for measuring absorption spectrum disclosed by the application has the advantages that the sapphire carrier is arranged to carry the object to be detected, the light source is arranged to project light to the object to be detected, and the fiber probe is arranged to receive light reflected from the object to be detected, so that the overall structure is simple, the opaque sample and irregular solid sample (such as a gemstone) can be quickly and simply measured in terms of ultraviolet-visible-near infrared absorption spectrum, the signal of detection is good, and the measurement accuracy is high.

Description

Technical Field

[0001] This invention relates to the field of solid absorption spectroscopy measurement technology, and more particularly to an integrating sphere for measuring absorption spectra and a method thereof. Background Technology

[0002] Under the influence of electromagnetic radiation, a type of ultraviolet-visible molecular spectrum produced by the transition of electrons between energy levels in molecules is called ultraviolet-visible absorption spectroscopy. For gemstones, most are inorganic compounds, and inorganic substances exhibit two types of electronic transitions: ligand field transitions and charge migration transitions. By measuring the information reflected in the ultraviolet-visible absorption spectrum of gemstones, we can explore the color development mechanism, evaluate the color quality, and analyze the composition, origin, and authenticity of the gemstones.

[0003] Currently, the mainstream testing methods are the direct projection method and the reflection method. The direct projection method involves directly illuminating the gemstone sample with a beam of light. After the photometer collects the transmitted light, it automatically calculates the intensity of the two beams and converts it into a function curve of absorbance versus wavelength. However, gemstone samples usually have a certain thickness, and when the sample is a dark-colored gemstone, the transmittance is very poor. Furthermore, gemstone samples have many irregular surfaces and strong light scattering, which greatly limits the application of the direct projection method. The most commonly used method in the reflection method is the spectrophotometer with an integrating sphere. However, existing reflection methods, due to the limitations of the integrating sphere structure, have a small light reflection and absorption area on the sample, resulting in poor detection signal and low accuracy. Summary of the Invention

[0004] In view of this, the first aspect of the present invention discloses an integrating sphere for measuring absorption spectra, which can quickly and easily measure the ultraviolet-visible-near-infrared absorption spectra of opaque samples and irregular solid samples (such as gemstones), and the light reflection and absorption area of ​​the sample to be tested is large, resulting in good detection signal and high accuracy.

[0005] To achieve the above objectives, the first aspect of the present invention provides the following technical solution:

[0006] An integrating sphere for measuring absorption spectra, comprising:

[0007] A spherical shell with an internal cavity;

[0008] A sapphire carrier, which is disposed in the inner cavity and is used to hold the item to be tested;

[0009] A light source, which is mounted on the spherical housing, is used to project light onto the object to be tested;

[0010] An optical fiber probe, mounted on the spherical housing, is used to receive light reflected directly or indirectly from the object to be tested.

[0011] A second aspect of the present invention provides a measurement method, comprising:

[0012] The light emitted by the light source passes through the sapphire carrier and is projected onto the item to be tested;

[0013] The light passes through the object to be tested and is reflected to the fiber optic probe, or the light passes through the object to be tested and is reflected by the inner wall of the spherical shell to the fiber optic probe;

[0014] The ultraviolet-visible-near-infrared absorption spectrum of the item to be tested is obtained by analyzing the light received by the fiber optic probe.

[0015] As can be seen from the above technical solution, the integrating sphere for measuring absorption spectra disclosed in this invention uses a sapphire carrier to support the object to be tested, a light source to project light onto the object, and an optical fiber probe to receive the light reflected from the object. The overall structure is simple, allowing for rapid and easy measurement of the ultraviolet-visible-near-infrared absorption spectra of opaque and irregular solid samples (such as gemstones). Furthermore, the large light reflection and absorption area of ​​the object results in a good detection signal and high measurement accuracy. In addition, sapphire possesses advantages such as high spectral transmittance (over 85%) in the ultraviolet-visible band, high strength, thermal shock resistance, radiation resistance, oxidation resistance, good abrasion resistance, strong corrosion resistance, chemical stability, and no grain boundary scattering. Using a sapphire carrier to support the object is highly beneficial for its testing. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic cross-sectional view of an integrating sphere for measuring absorption spectra provided in an embodiment of the present invention;

[0018] Figure 2 yes Figure 1 A magnified view of a portion of point A in the middle;

[0019] Figure 3 This is a cross-sectional schematic diagram of a sapphire carrier provided in an embodiment of the present invention;

[0020] Figure 4 This is a cross-sectional schematic diagram of a sapphire carrier provided in another embodiment of the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0023] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0024] Please see Figure 1-4 The first aspect of the present invention discloses an integrating sphere 100 for measuring absorption spectra, comprising a spherical shell 10, a sapphire carrier 20, a light source 30, and an optical fiber probe 40. The spherical shell 10 has an inner cavity 101, the sapphire carrier 20 is disposed in the inner cavity 101, the sapphire carrier 20 is used to hold an item 200 to be tested, the light source 30 is mounted on the spherical shell 10, the light source 30 is used to project light onto the item 200 to be tested, and the optical fiber probe 40 is mounted on the spherical shell 10, the optical fiber probe 40 is used to receive light reflected from the item 200 to be tested.

[0025] In use, the light emitted by the light source 30 illuminates the item 200 to be tested. The light is then reflected from the item 200 to the fiber optic probe 40. Alternatively, the light may illuminate the item 200, reflect onto the inner surface of the spherical housing 10, and then reflect again to the fiber optic probe 40. By analyzing the light collected by the fiber optic probe 40, the operator can obtain the ultraviolet-visible absorption spectrum of the item 200, thereby determining its colorimetric mechanism and color quality.

[0026] In one application scenario, the integrating sphere 100 for measuring absorption spectra is used to measure the ultraviolet-visible absorption spectrum of gemstones, thereby enabling the exploration of the color development mechanism of gemstones and the evaluation of their color quality.

[0027] By adopting the above technical solution, a sapphire carrier 20 is used to support the item 200 to be tested, a light source 30 is used to project light onto the item 200, and an optical fiber probe 40 is used to receive the light reflected from the item 200. The overall structure is simple and can quickly and easily measure the ultraviolet-visible-near-infrared absorption spectrum of opaque samples and irregular solid samples (such as gemstones). Moreover, the light reflection and absorption area of ​​the item to be tested is large, resulting in a good detection signal and high measurement accuracy. In addition, sapphire has the advantages of high spectral transmittance (above 85%) in the ultraviolet-visible band, high strength, good thermal shock resistance, radiation resistance, oxidation resistance, good abrasion resistance, strong corrosion resistance, chemical stability, and no grain boundary scattering. Using a sapphire carrier 20 to support the item to be tested is very beneficial for the detection of the item.

[0028] In an optional embodiment, the spherical shell 10 includes a lower shell 11 and an upper shell 12. The lower shell 11 is hemispherical, and the upper shell 12 is hemispherical. The upper shell 12 and the lower shell 11 are detachably connected. A sapphire carrier 20 is horizontally disposed at the connection between the upper shell 12 and the lower shell 11. Preferably, the sapphire carrier 20 is disc-shaped. By setting the sapphire carrier 20 horizontally at the connection between the upper shell 12 and the lower shell 11, that is, the sapphire carrier 20 coincides with the equatorial plane of the spherical shell 10, the item 20 to be detected, by placing it at the center point of the sapphire carrier 20, is equivalent to the item 200 being located at the center of the spherical shell 10. The item 200 to be detected can fully receive the light reflected from the inner wall surface of the spherical shell 10, thereby improving the accuracy of the detection.

[0029] For example, the upper housing 12 and the lower housing 11 are connected by threads. Specifically, one end of the upper housing 12 connected to the lower housing 11 has an internal thread, and the other end of the lower housing 11 connected to the upper housing 12 has an external thread. The upper housing 12 and the lower housing 11 are connected by the engagement of the internal and external threads. In an optional embodiment, the height of the threaded section of the upper housing 12 and the lower housing 11 can be 5 cm. Understandably, to prevent external light from entering the inner cavity 101 from the joint of the upper housing 12 and the lower housing 11 and affecting the detection results, the thread pitch of the threaded section of the upper housing 12 and the lower housing 11 can be set to be relatively close, thereby preventing external light from entering the inner cavity 101. By setting the upper housing 12 and the lower housing 11 to be connected by threads, the operator can easily open the upper housing 12 and place the item 200 to be tested for detection, making the operation simple.

[0030] In an optional embodiment, the outer side wall of the lower housing 11 is provided with an annular boss 111, and the gemstone carrier 20 is placed on the annular boss 111. Preferably, the width of the annular boss 111 is 5 mm and the thickness is 2 mm.

[0031] In an optional embodiment, the surface of the annular boss 111 is coated with a layer of diffuse reflective material.

[0032] For example, a support 13 is installed on the side of the lower housing 11 away from the upper housing 12, and the spherical housing 10 can be placed on the ground via the support 13.

[0033] In an optional embodiment, the sapphire carrier 20 has a protruding locking block 21 for holding the item 200 to be tested. The locking block 21 is made of sapphire material. By setting the locking block 21, the item 200 to be tested can be clamped and fixed, which facilitates the testing process. In addition, by using sapphire material for the locking block 21, it has the advantages mentioned above, such as high spectral transmittance (above 85%) in the ultraviolet-visible band, high strength, thermal shock resistance, radiation resistance, oxidation resistance, good abrasion resistance, strong corrosion resistance, chemical stability, and no grain boundary scattering.

[0034] Understandably, the sapphire carrier 20 is not limited to holding the item 200 to be tested by protruding the latch 21. For example, the sapphire carrier 20 can also hold the item 200 to be tested by recessing the latch 22.

[0035] In an optional embodiment, the sapphire carrier 20 is provided with a lifting member 23, which is used by the user to move the sapphire carrier 20. Preferably, there are two lifting members 23, which are located on opposite sides of the sapphire carrier 20 and are arranged symmetrically.

[0036] In an optional embodiment, the light source 30 is disposed within the lower housing 11. By placing the light source 30 within the lower housing 11, that is, placing the light source 30 inside the spherical housing 10, the loss of the light source 30 due to transmission can be reduced, and the integration of the device is higher for the entire integrating sphere 100 used to measure the absorption spectrum. Of course, the light source 30 can also be mounted outside the spherical housing 10, for example, by opening a light-entry hole in the spherical housing 10, so that the light emitted by the light source 30 can enter the inner cavity 101 through the light-entry hole.

[0037] In an optional embodiment, the light source 30 is a xenon lamp, which has the advantages of long lifespan, low power consumption, and high brightness compared to other light sources.

[0038] In an optional embodiment, the fiber optic probe 40 is mounted on the lower housing. That is, the fiber optic probe 40 and the light source 30 are located on the same side of the sapphire carrier 20, so that the light detected by the fiber optic probe 40 is the light after passing through the object to be tested 200, rather than the light from the light source 30 itself. If the fiber optic probe 40 is mounted on the upper housing, the fiber optic probe 40 is very susceptible to the influence of the xenon lamp. The xenon lamp light source is much stronger than the light after absorption by the sample, which will reduce the signal-to-noise ratio and may extinguish the signal to be measured.

[0039] In an optional embodiment, the integrating sphere 100 for measuring the absorption spectrum further includes a light-shielding element 14. The light-shielding element 14 is disposed at the fiber optic probe 40 and includes a first shield 141 and a second shield 142. The first shield 141 is disposed on the side of the fiber optic probe 40 facing the light source 30, and one end of the first shield 141 is connected to the inner sidewall of the spherical shell 10. One end of the second shield 142 is connected to the end of the first shield 141 away from the spherical shell 10, and the other end extends away from the light source 30. The purpose of providing the light-shielding element 14 is to block the light source 30, reduce the influence of light from the light source 30 that is not projected onto the object under test 200 on the fiber optic probe 40, thereby improving the detection accuracy.

[0040] In an optional embodiment, the surface of the light-shielding member 14 is coated with a layer of diffuse reflective material.

[0041] In an optional embodiment, the inner wall surface of the spherical shell 10 is coated with a diffuse reflective material layer 102.

[0042] By spraying a diffuse reflection material layer onto the surface of the light-shielding member 14 and the inner wall of the spherical shell 10, light will be reflected in all directions when it is projected onto the surface of the light-shielding member 14 and the inner wall of the spherical shell 10, so that the light can be mixed evenly and the detection accuracy can be improved.

[0043] In an optional embodiment, the diffuse reflective material layer is a polytetrafluoroethylene (PTFE) layer. The PTFE coating has a reflectivity of nearly 100% in the 200-2500nm wavelength band, excellent directionality, and good stability, making it difficult to fall off into powder.

[0044] A second aspect of the present invention provides a measurement method for the above-described integrating sphere, the measurement method comprising:

[0045] The light emitted by the light source passes through the sapphire carrier and is projected onto the item to be tested;

[0046] The light passes through the object to be tested and is reflected to the fiber optic probe, or the light passes through the object to be tested and is reflected by the inner wall of the spherical shell to the fiber optic probe;

[0047] The ultraviolet-visible-near-infrared absorption spectrum of the item to be tested is obtained by analyzing the light received by the fiber optic probe.

[0048] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An integrating sphere for measuring absorption spectra, characterized in that, include: A spherical shell includes an upper shell and a lower shell, wherein the upper shell is hemispherical and the lower shell is hemispherical and detachably connected to the upper shell, and the upper shell and the lower shell together form an inner cavity; A sapphire carrier is disposed in the inner cavity and horizontally positioned at the connection between the upper and lower housings for carrying the item to be tested. The sapphire carrier is provided with a lifting member for the user to move the sapphire carrier. A light source, which is installed in the spherical housing, is used to project light onto the object to be tested, and the light source is located inside the lower housing; An optical fiber probe is mounted on the spherical housing and is used to receive light reflected directly or indirectly from the object to be detected. The optical fiber probe is also mounted on the lower housing. A light-shielding component is provided at the fiber optic probe to block the light source.

2. The integrating sphere for measuring absorption spectra according to claim 1, characterized in that, The sapphire carrier has a protruding locking block for holding the item to be inspected; the locking block is made of sapphire material. Alternatively... The sapphire carrier has a recessed slot for holding the item to be tested.

3. The integrating sphere for measuring absorption spectra according to claim 1, characterized in that, The light-shielding component includes: A first shield is disposed on the side of the fiber optic probe facing the light source, and one end of the first shield is connected to the inner wall of the spherical shell. The second shield has one end connected to the end of the first shield away from the spherical shell, and the other end extending away from the light source.

4. The integrating sphere for measuring absorption spectra according to claim 1, characterized in that, The surface of the light-shielding component is coated with a layer of diffuse reflective material.

5. The integrating sphere for measuring absorption spectra according to claim 1, characterized in that, The inner wall of the spherical shell is coated with a layer of diffuse reflective material.

6. A measurement method for an integrating sphere for measuring absorption spectra according to any one of claims 1-5, characterized in that, The measurement method includes: The light emitted by the light source passes through the sapphire carrier and is projected onto the item to be tested; The light passes through the object to be tested and is reflected to the fiber optic probe, or the light passes through the object to be tested and is reflected by the inner wall of the spherical shell to the fiber optic probe; The ultraviolet-visible-near-infrared absorption spectrum of the item to be tested is obtained by analyzing the light received by the fiber optic probe.

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