Large dynamic range radiation temperature measurement system and temperature measurement method based on optical fiber light splitting

Abstract

The invention provides a large dynamic range radiation temperature measurement system and a temperature measurement method based on optical fiber light splitting, and mainly solves the technical problem that a large dynamic range temperature measurement requirement cannot be met when an existing radiation temperature measurement instrument selects a relatively short wavelength for temperature measurement. The radiation temperature measurement system comprises an optical module, an acquisition module and a calculation module which are connected in sequence, the optical module comprises a light collecting unit and a light splitting unit; the light collecting unit is used for receiving a light signal reflected by a target object; one end of the light splitting unit is a common end, the other end of the light splitting unit is a branch end, and the common end is coupled with the output end of the light collecting unit; the branch end is composed of n optical fiber bundles, n is larger than or equal to 2, and each optical fiber bundle comprises a plurality of optical fibers. The acquisition module comprises m photoelectric detectors, wherein m is greater than or equal to 2 and less than or equal to n; each photoelectric detector is connected with one of the n optical fiber bundles and used for collecting optical signals transmitted by the light collecting unit and the corresponding optical fiber bundle, converting the optical signals into electric signals and transmitting the electric signals to the calculation module.

Description

Technical Field

[0001] The present invention relates to radiation temperature measurement equipment, and particularly to a large dynamic range radiation temperature measurement system and temperature measurement method based on optical fiber spectroscopy. Background Art

[0002] Radiation temperature measurement is a non-contact temperature measurement method with characteristics such as high speed and high precision. Existing radiation thermometers generally consist of parts such as an optical system, a photoelectric detector, a signal amplifier, and a signal processing circuit. The optical system collects the target infrared radiation energy within its field of view, and the infrared radiation energy is focused on the photoelectric detector and converted into a corresponding electrical signal. This signal is converted into the temperature value of the measured target through an amplifier and a signal processing circuit, thereby realizing the measurement of the temperature of the measured target.

[0003] However, when the radiation thermometer measures temperature, the change in the surrounding temperature has a great influence on the radiation energy, that is, the dynamic range of the infrared radiation energy with temperature changes extremely violently. Using a conventional radiation thermometer with a shorter wavelength simply cannot meet the requirements of a large dynamic temperature measurement range of thousands to tens of thousands of times. For example, for a signal light with a central wavelength of 900 nm, the radiation intensity at 1000 degrees differs from that at 200 degrees by nine orders of magnitude. Therefore, it brings a huge burden to the subsequent circuit design, and at the same time, it will also introduce various device noises, resulting in many problems such as accuracy loss and dynamic range limitation. Summary of the Invention

[0004] The purpose of the present invention is to provide a large dynamic range radiation temperature measurement system and temperature measurement method based on optical fiber spectroscopy, mainly solving the technical problem that when the existing radiation thermometer uses a shorter wavelength for temperature measurement, it cannot meet the requirements of a large dynamic range temperature measurement.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] A large dynamic range radiation temperature measurement system based on optical fiber spectroscopy, characterized in that:

[0007] It includes an optical module, an acquisition module, and a calculation module connected in sequence;

[0008] The optical module includes a light collection unit and a spectroscopic unit; the light collection unit is used to receive the optical signal radiated by the target object; one end of the spectroscopic unit is a common end, and the other end is a branch end. Among them, the common end is coupled to the output end of the light collection unit; the branch end consists of n fiber bundles, and n≥2. Each fiber bundle includes several optical fibers;

[0009] The acquisition module includes m photodetectors, where n ≥ m ≥ 2; each photodetector is respectively connected to one of the n fiber optic bundles, and is used to collect the optical signals transmitted through the light collection unit and the corresponding fiber optic bundle, and convert them into electrical signals and transmit them to the calculation module;

[0010] The calculation module is used to calculate the received electrical signals to obtain the temperature value of the target object.

[0011] Further, the light collection unit is a light pipe or an optical lens.

[0012] Further, it also includes m filter plates respectively arranged at the input ends of the m photodetectors and corresponding to each photodetector one by one, and the working wavelength ranges of each filter plate are the same.

[0013] Further, it also includes m filter plates respectively arranged at the input ends of the m photodetectors and corresponding to each photodetector one by one. When m ≥ 3, the working wavelength range of at least one filter plate is different from that of other filter plates, and at least two filter plates are within the same wavelength range.

[0014] Further, the filter plate is a band-pass filter plate.

[0015] Further, it also includes an indicating light source. The indicating light source is connected to one of the n fiber optic bundles that is not connected to the photodetector. The indicating light emitted by the indicating light source reaches the surface of the target object after passing through the corresponding fiber optic bundle and the light collection unit, and is used for auxiliary aiming.

[0016] Further, the material of the optical fiber in each fiber optic bundle is quartz, multi-component glass or plastic;

[0017] The types of the m photodetectors are all the same, or all different, or partially the same;

[0018] The material of the light pipe is sapphire or quartz.

[0019] The present invention also provides a large dynamic range radiation temperature measurement method based on fiber optic beam splitting. The special feature is that the above-mentioned large dynamic range radiation temperature measurement system based on fiber optic beam splitting is adopted, including the following steps:

[0020] Step 1, the light collection unit receives the optical signals radiated by the target object;

[0021] Step 2, after the optical signals are coupled through the common end of the beam splitting unit, they are output by the n fiber optic bundles at the branch end and are respectively received by m photodetectors;

[0022] Step 3, the m photodetectors respectively convert the received optical signals into electrical signals and then input them into the calculation module;

[0023] Step 4: The calculation module calculates the electrical signals output by each photodetector respectively and outputs the temperature value of the target object surface.

[0024] Further, in Step 2, by controlling the number of fiber bundles and the number of optical fibers in each fiber bundle, the energy dynamic range of the optical signal is expanded, thereby increasing the temperature range.

[0025] Further, it further includes the step of irradiating the indicating light emitted by the indicating light source onto the target object surface through one of the n fiber bundles at the branching end and the light collecting unit for auxiliary aiming.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The large dynamic range radiation temperature measurement system based on optical fiber splitting in the present invention divides the same beam of signal light into n branches with a large energy difference by allocating the corresponding number of optical fibers to each fiber bundle in the splitting unit according to the design requirements, and the branches are respectively received by photodetectors. Finally, the temperature value of the target object is obtained through calculation by the calculation module. This splitting method greatly expands the energy dynamic range of the radiation temperature measurement system, thereby significantly increasing the temperature range.

[0028] 2. The large dynamic range radiation temperature measurement system based on optical fiber splitting in the present invention can also be provided with an indicating light source according to needs, which is convenient for auxiliary aiming of the target object and improves the measurement efficiency.

[0029] 3. The large dynamic range radiation temperature measurement method based on optical fiber splitting in the present invention is simple, convenient, and has strong applicability. Description of the Drawings

[0030] Figure 1 It is a schematic structural diagram of the light collecting unit as a light guide tube in the embodiment of the large dynamic range radiation temperature measurement system based on optical fiber splitting in the present invention.

[0031] Figure 2 It is a schematic structural diagram of the light collecting unit as an optical lens in the embodiment of the large dynamic range radiation temperature measurement system based on optical fiber splitting in the present invention.

[0032] Figure 3 It is a schematic structural diagram of the optical module and the acquisition module in the first embodiment of the large dynamic range radiation temperature measurement system based on optical fiber splitting in the present invention.

[0033] Figure 4 It is a schematic structural diagram of the optical module and the acquisition module in the second embodiment of the large dynamic range radiation temperature measurement system based on optical fiber splitting in the present invention.

[0034] Figure 5This is a schematic structural diagram of the optical module and the acquisition module in Embodiment 3 and Embodiment 4 of the large dynamic range radiation temperature measurement system based on fiber optic beam splitting according to the present invention.

[0035] Figure 6 This is a schematic structural diagram of the optical module and the acquisition module in Embodiment 5 of the large dynamic range radiation temperature measurement system based on fiber optic beam splitting according to the present invention.

[0036] Figure 7 This is a schematic structural diagram of the optical module and the acquisition module in Embodiment 6 of the large dynamic range radiation temperature measurement system based on fiber optic beam splitting according to the present invention.

[0037] Figure 8 This is a schematic structural diagram of the optical module and the acquisition module in Embodiment 7 and Embodiment 8 of the large dynamic range radiation temperature measurement system based on fiber optic beam splitting according to the present invention.

[0038] The reference numerals are as follows:

[0039] 1 - light collecting unit, 2 - beam splitting unit, 21 - fiber optic bundle, 3 - indicating light source, 4 - photodetector. Detailed implementation manners

[0040] For a radiation thermometer using multiple wavelengths, the dynamic range of its shorter wavelength is often several orders of magnitude larger than that of its longer wavelength. Therefore, the present invention expands the measurement dynamic range by using a beam splitting method, meeting the actual technical needs of the radiation thermometer in a larger measurement range.

[0041] As Figure 1 and Figure 2 shown, the present invention provides a large dynamic range radiation temperature measurement system based on fiber optic beam splitting, including an optical module, an acquisition module and a calculation module connected in sequence.

[0042] Among them, the optical module includes a light collecting unit 1 and a beam splitting unit 2; the light collecting unit 1 is used to receive the optical signal (i.e., radiation energy) radiated by the target object itself. One end of the beam splitting unit 2 is a common end, and the other end is a branched end. Among them, the common end is coupled to the output end of the light collecting unit 1; the branched end is composed of n fiber optic bundles 21, and n≥2. Each fiber optic bundle 21 includes a plurality of optical fibers, and the specific quantity can be designed according to the actual measurement requirements, so that the energy intensity of each fiber optic bundle can differ by five or more orders of magnitude, thereby expanding the dynamic range of the photodetector and increasing the temperature range, meeting the requirements of large dynamic range temperature measurement.

[0043] The beam splitting unit 2 can select an optical duct ( Figure 1 shown) or an optical lens ( Figure 2 shown).

[0044] The acquisition module includes m photodetectors 4, where n ≥ m ≥ 2; each photodetector 4 is respectively connected to one of the n fiber optic bundles 21, and is used to collect the optical signal transmitted through the light collection unit 1 and the corresponding fiber optic bundle 21, and convert it into an electrical signal and transmit it to the calculation module. The calculation module is used to calculate the received electrical signal to obtain the temperature value of the target object.

[0045] The present invention also provides a large dynamic range radiation temperature measurement method based on fiber optic beam splitting, including the following steps:

[0046] Step 1, the light collection unit 1 receives the optical signal radiated by the target object.

[0047] Step 2, after the optical signal is coupled through the common end of the beam splitting unit 2, it is output by the n fiber optic bundles 21 at the branch end and received by the corresponding m photodetectors 4.

[0048] Step 3, the m photodetectors 4 respectively convert the received optical signal into an electrical signal and input it into the calculation module.

[0049] Step 4, the calculation module calculates the electrical signals output by each photodetector 4 respectively, and outputs the temperature value on the surface of the target object, thereby realizing large dynamic range radiation temperature measurement.

[0050] By reasonably adjusting the beam splitting ratio among the m channels of detectors, the present invention can improve the dynamic range of the radiation temperature measurement system, and further improve the temperature range of the radiation temperature measurement system. The applicable energy range of the existing single acquisition circuit is only a times. After the present invention splits the light through the beam splitting unit into j channels with a ratio of k1:k2:……:kj, the dynamic range of the input radiation energy is expanded to k1*k2*...*kj*a times, and the corresponding temperature range is correspondingly expanded, thereby realizing large dynamic range radiation temperature measurement.

[0051] Next, the principle of fiber optic beam splitting of the present invention will be described in detail in conjunction with the drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0052] Embodiment 1

[0053] Refer to Figure 3 , the large dynamic range radiation temperature measurement system based on fiber optic beam splitting in this embodiment includes an optical duct, a beam splitting unit 2, two photodetectors 4, and an indicating light source 3.

[0054] The optical duct is a sapphire optical duct with a diameter of 3 mm and a length of 60 mm. The two photodetectors 4 are respectively two identical silicon detectors with a 920±30 nm filter.

[0055] The spectroscopic unit 2 is composed of 19 plastic optical fibers with a diameter of 500 μm. Its common end is coupled and connected to the 3-mm-diameter output end in the sapphire light pipe. The 19 optical fibers at the branched end of the spectroscopic unit 2 are divided into three strands. One strand with 1 fiber is connected to a silicon detector filtered at 920 ± 30 nm, one strand with 17 fibers is connected to another silicon detector filtered at 920 ± 30 nm, and one strand with 1 fiber is connected to the indicating light source 3. The indicating light emitted by the indicating light source 3 exits through the corresponding optical fiber, and then irradiates the surface of the target through the light pipe for auxiliary aiming. Through the two silicon detectors for energy distribution of 1:17, the energy dynamic range of the full range of 920 nm wavelength can be covered.

[0056] Embodiment 2

[0057] Refer to Figure 4 , the large dynamic range radiation temperature measurement system based on fiber optic spectroscopy in this embodiment includes a light pipe, a spectroscopic unit 2, and three photodetectors 4.

[0058] The light pipe is a sapphire light pipe with a diameter of 3 mm and a length of 60 mm. Among the three photodetectors 4, two of them are the same silicon detectors filtered at 920 ± 30 nm, and the other one is an indium gallium arsenide detector filtered at 1550 ± 30 nm.

[0059] The spectroscopic unit 2 is composed of 37 quartz optical fibers with a diameter of 250 μm. Its common end is coupled and connected to the 3-mm-diameter output end in the sapphire light pipe. The 37 optical fibers at the branched end of the spectroscopic unit 2 are divided into three strands. One strand with 1 fiber is connected to a silicon detector filtered at 920 ± 30 nm, one strand with 5 fibers is connected to an indium gallium arsenide detector filtered at 1550 ± 30 nm, and one strand with 31 fibers is connected to a silicon detector filtered at 920 ± 30 nm. Through the two silicon detectors for energy distribution of 1:31, the energy dynamic range of the full range of 920 nm wavelength is further expanded.

[0060] Embodiment 3

[0061] Refer to Figure 5 , the large dynamic range radiation temperature measurement system based on fiber optic spectroscopy in this embodiment includes a light pipe, a spectroscopic unit 2, and four photodetectors 4.

[0062] The light pipe is a sapphire light pipe with a diameter of 3 mm and a length of 60 mm. Among the four photodetectors 4, two of them are the same silicon detectors filtered at 920 ± 30 nm, and the other two are the same indium gallium arsenide detectors filtered at 1550 ± 30 nm.

[0063] The spectral splitting unit 2 is composed of 1000 multi-component glass multi-core optical fibers with a diameter of 9 μm. Its common end 21 is coupled and connected to the 3-mm-diameter output end in the sapphire light guide tube. The 1000 optical fibers at the branched end of the spectral splitting unit 2 are divided into four strands. One strand of 10 fibers is connected to an indium gallium arsenide detector filtered at 1550 ± 30 nm, one strand of 490 fibers is connected to another indium gallium arsenide detector filtered at 1550 ± 30 nm, one strand of 10 fibers is connected to a silicon detector filtered at 920 ± 30 nm, and one strand of 490 fibers is connected to another silicon detector filtered at 920 ± 30 nm. The energy is distributed in a ratio of 1:49 through two groups of detectors respectively, so as to expand the energy dynamic range of the full range of 920-nm wavelength and 1550-nm wavelength respectively.

[0064] Example 4

[0065] Refer to Figure 5 , the large dynamic range radiation temperature measurement system based on optical fiber spectral splitting in this embodiment includes a light guide tube, a spectral splitting unit 2, and four photodetectors 4.

[0066] The light guide tube is a sapphire light guide tube with a diameter of 3 mm and a length of 60 mm. Among the four photodetectors 4, one is the same silicon detector filtered at 920 ± 30 nm, two are silicon detectors filtered at 750 ± 30 nm, and the other is an indium gallium arsenide detector filtered at 1550 ± 30 nm.

[0067] The spectral splitting unit 2 is composed of 37 quartz optical fibers with a diameter of 250 μm. Its common end is coupled and connected to the 3-mm-diameter output end in the sapphire light guide tube. The 37 optical fibers at the branched end of the spectral splitting unit 2 are divided into four strands. One strand of 1 fiber is connected to a silicon detector filtered at 750 ± 30 nm, one strand of 1 fiber is connected to a silicon detector filtered at 920 ± 30 nm, one strand of 1 fiber is connected to an indium gallium arsenide detector filtered at 1550 ± 30 nm, and one strand of 34 fibers is connected to another silicon detector filtered at 750 ± 30 nm. The energy is distributed in a ratio of 1:34 through two silicon detectors filtered at 750 ± 30 nm, so as to expand the energy dynamic range of the full range of 750-nm wavelength.

[0068] Example 5

[0069] Refer to Figure 6 , the large dynamic range radiation temperature measurement system based on optical fiber spectral splitting in this embodiment includes a light guide tube, a spectral splitting unit 2, three photodetectors 4, and an indicating light source 3.

[0070] The light guide tube is a sapphire light guide tube with a diameter of 3 mm and a length of 60 mm. The three photodetectors 4 are all the same silicon detectors without filters.

[0071] The spectroscopic unit 2 is composed of 37 quartz optical fibers with a diameter of 250 μm. Its common end is coupled to the 3-mm-diameter exit end in the sapphire light guide tube. The 37 optical fibers at the branched end of the spectroscopic unit 2 are divided into four strands. One strand with 1 optical fiber is connected to the first silicon detector without a filter, one strand with 5 optical fibers is connected to the second silicon detector without a filter, one strand with 30 optical fibers is connected to the third detector without a filter, and one strand with 1 optical fiber is connected to the indicating light source 3. The indicating light emitted by the indicating light source 3 exits through one strand of optical fiber, and then irradiates the object to be measured through the light guide tube for auxiliary aiming. The energy is distributed in a ratio of 1:5:30 by the three silicon detectors, thereby expanding the energy dynamic range of the full scale.

[0072] Example Six

[0073] Refer to Figure 7 , the large-dynamic-range radiation temperature measurement system based on fiber optic spectroscopy in this example includes an optical lens, a spectroscopic unit 2, two photodetectors 4, and an indicating light source 3.

[0074] The optical lens is a lens with a focal length of 50 mm and an aperture of 24 mm. The two photodetectors 4 are both the same silicon detectors filtered at 920 ± 30 nm.

[0075] The spectroscopic unit 2 is composed of 19 quartz optical fibers with a diameter of 125 μm. Its common end is set at the image point of the optical lens. The 19 optical fibers at the branched end of the spectroscopic unit 2 are divided into three strands. One strand with 1 optical fiber is connected to the silicon detector filtered at 920 ± 30 nm, one strand with 17 optical fibers is connected to another silicon detector filtered at 920 ± 30 nm, and one strand with 1 optical fiber is connected to the indicating light source 3. The indicating light emitted by the indicating light source 3 exits through one strand of optical fiber, and then irradiates the object to be measured through the light guide tube for auxiliary aiming. The energy dynamic range of the full scale is covered by the energy distribution of 1:17 by the two detectors.

[0076] Example Seven

[0077] Refer to Figure 8 , the large-dynamic-range radiation temperature measurement system based on fiber optic spectroscopy in this example includes an optical lens, a spectroscopic unit 2, and four photodetectors 4.

[0078] The optical lens is a lens with a focal length of 70 mm and an aperture of 24 mm. Among the four photodetectors 4, two are the same silicon detectors filtered at 920 ± 30 nm, and the other two are the same indium gallium arsenide detectors filtered at 1550 ± 30 nm.

[0079] The spectroscopic unit 2 is composed of 1000 multi-component glass multi-core optical fibers with a diameter of 9 μm, and its common end is set at the image point of the optical lens. The 1000 optical fibers at the branched end of the spectroscopic unit 2 are divided into four strands. One strand of 10 fibers is connected to a silicon detector with a 1550 ± 30 nm filter, one strand of 490 fibers is connected to another silicon detector with a 1550 ± 30 nm filter, one strand of 10 fibers is connected to an indium gallium arsenide detector with a 920 ± 30 nm filter, and one strand of 490 fibers is connected to another indium gallium arsenide detector with a 920 ± 30 nm filter. Through the energy distribution of 1:49 of the two groups of detectors, the energy dynamic range of the full range of wavelengths of 920 nm and 1550 nm is respectively expanded.

[0080] Example VIII

[0081] Referring to Figure 8 , the large dynamic range radiation temperature measurement system based on fiber optic spectroscopy in this embodiment includes an optical lens, a spectroscopic unit 2, and four photodetectors 4.

[0082] The optical lens is a lens with a focal length of 70 mm and an aperture of 20 mm. Among the four photodetectors 4, one is a silicon detector with a 920 ± 30 nm filter, two are the same silicon detectors with a 750 ± 30 nm filter, and the remaining one is an indium gallium arsenide detector with a 1550 ± 30 nm filter.

[0083] The spectroscopic unit 2 is composed of 1000 multi-component glass multi-core optical fibers with a diameter of 9 μm, and its common end is set at the image point of the optical lens. The 1000 optical fibers at the branched end of the spectroscopic unit 2 are divided into four strands. One strand of 10 fibers is connected to an indium gallium arsenide detector with a 1550 ± 30 nm filter, one strand of 10 fibers is connected to a silicon detector with a 920 ± 30 nm filter, one strand of 10 fibers is connected to a silicon detector with a 750 ± 30 nm filter, and one strand of 970 fibers is connected to another silicon detector with a 750 ± 30 nm filter. Through the energy distribution of 1:97 of the two silicon detectors with a 750 ± 30 nm filter, the energy dynamic range of the full range of the 750 nm wavelength is expanded.

[0084] Based on the above embodiments, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of protection of the present invention.

Claims

1. A large dynamic range radiation temperature measurement system based on optical fiber spectroscopy, characterized in that: It includes an optical module, an acquisition module and a calculation module connected in sequence; The optical module includes a light collecting unit (1) and a spectroscopic unit (2); the light collecting unit (1) is used to receive the optical signal radiated by the target object; one end of the spectroscopic unit (2) is a common end, and the other end is a branch end, wherein the common end is coupled to the output end of the light collecting unit (1); the branch end is composed of n optical fiber bundles (21), and n≥2, and each optical fiber bundle (21) includes several optical fibers; The acquisition module includes m photodetectors (4), where n≥m≥2; each photodetector (4) is respectively connected to one of the n optical fiber bundles (21), and is used to collect the optical signal transmitted by the light collecting unit (1) and the corresponding optical fiber bundle (21), and convert it into an electrical signal and transmit it to the calculation module; The calculation module is used to calculate the received electrical signal to obtain the temperature value of the target object.

2. The large dynamic range radiation temperature measurement system based on optical fiber spectroscopy according to claim 1, characterized in that: The light collecting unit (1) is a light pipe or an optical lens.

3. The large dynamic range radiation temperature measurement system based on optical fiber spectroscopy according to claim 2, characterized in that: It further includes m filter films respectively arranged at the input ends of the m photodetectors (4) and corresponding to each photodetector (4) one by one, and the working wavelength ranges of each filter film are the same.

4. The large dynamic range radiation temperature measurement system based on optical fiber spectroscopy according to claim 2, characterized in that: It further includes m filter films respectively arranged at the input ends of the m photodetectors (4) and corresponding to each photodetector (4) one by one. When m≥3, the working wavelength range of at least one filter film is different from that of other filter films, and at least two filter films are in the same wavelength range.

5. The large dynamic range radiation temperature measurement system based on optical fiber spectroscopy according to claim 3 or 4, characterized in that: The filter film is a band-pass filter film.

6. The large dynamic range radiation temperature measurement system based on optical fiber spectroscopy according to claim 5, characterized in that: It further includes an indicating light source (3), and the indicating light source (3) is connected to one of the n optical fiber bundles (21) that is not connected to the photodetector (4). The indicating light emitted by the indicating light source (3) reaches the surface of the target object after passing through the corresponding optical fiber bundle (21) and the light collecting unit (1), and is used for auxiliary aiming.

7. The large dynamic range radiation temperature measurement system based on optical fiber spectroscopy according to claim 6, characterized in that: The material of the optical fiber in each optical fiber bundle (21) is quartz, multi-component glass or plastic; The types of the m photodetectors (4) are all the same, or all different, or partially the same and partially different; The material of the light pipe is sapphire or quartz.

8. A large dynamic range radiation temperature measurement method based on optical fiber beam splitting, characterized in that Using the large dynamic range radiation temperature measurement system based on optical fiber spectroscopy according to any one of claims 1 to 7, includes the following steps: Step 1, the light collecting unit (1) receives the optical signal radiated by the target object; Step 2: After the optical signal is coupled through the common end of the optical splitting unit (2), it is output by the n fiber bundles (21) at the branching end and received by m photodetectors (4) respectively; Step 3: The m photodetectors (4) respectively convert the received optical signals into electrical signals and then input them into the calculation module; Step 4: The calculation module respectively calculates the electrical signals output by each photodetector (4) and outputs the temperature value of the target object surface.

9. The large dynamic range radiation temperature measurement method based on optical fiber splitting according to claim 8, characterized in that: In step 2, by controlling the number of strands of the fiber bundle (21) and the number of optical fibers in each strand of the fiber bundle (21), the energy dynamic range of the optical signal is expanded, thereby increasing the temperature range.

10. The large dynamic range radiation temperature measurement method based on optical fiber splitting according to claim 8 or 9, characterized in that: It further includes a step of irradiating the target object surface for auxiliary aiming by passing the indicating light emitted by the indicating light source (3) through one of the n fiber bundles (21) at the branching end and the light collecting unit (1).

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