Low-temperature attenuation test qualified optical fiber, test method, test tool and test system

Abstract

The present invention discloses a qualified optical fiber for low-temperature attenuation test, a test method, a test tool and a test system. The method includes: winding an optical fiber around an optical fiber low-temperature attenuation performance test disc with a predetermined winding tension, and performing transmission characteristic tests on the coiled optical fiber under predetermined test conditions. Among them, the optical fiber low-temperature attenuation performance test disc includes a shaft body and baffles arranged on both sides of the shaft body, and a buffer material is provided on the shaft body. The test method, test tool and test system provided by the present invention can perform reliable low-temperature attenuation performance tests on long-distance optical fibers, avoiding the problem of waste caused by truncating the optical fiber to a length of 2 kilometers in the existing national standard test method; the optical fiber with qualified low-temperature attenuation performance provided by the present invention is qualified for low-temperature attenuation at each point over a long distance, and is suitable for long-distance information transmission in harsh environment areas such as extremely cold and hot or with extremely large day-night temperature differences.

Description

Technical Field

[0001] The present invention belongs to the field of optical fiber communication, and particularly relates to a fiber optic cable with qualified low-temperature attenuation, a testing method, a testing tool and a testing system. Background Art

[0002] As the only information carrier for optical communication transmission, optical fibers have the advantages of low attenuation, high bandwidth, stable transmission, etc., and are widely used in long-distance information transmission. The working temperature range of common optical fibers is generally -40 to 70°C. With the extension of the information network construction of operators to extremely cold, extremely hot or areas with extremely large temperature differences between day and night and other harsh environments, if the additional loss of the optical fiber at high or low temperatures is too large, the loss of the entire link will increase, and the transmission distance will be sharply reduced. Therefore, it is particularly important for optical fibers to have good low-temperature attenuation performance.

[0003] However, the existing optical fiber low-temperature attenuation testing method can only intercept 2-kilometer-long optical fibers for spot checks, and it is impossible to ensure that the optical fibers outside the sampling are all qualified for low-temperature attenuation. The truncated optical fibers cannot be used in the next process.

[0004] Therefore, it is necessary to develop a low-temperature attenuation testing method for long-distance optical fibers. Summary of the Invention

[0005] In view of the above technical problems, the present invention provides a fiber optic cable with qualified low-temperature attenuation, a testing method, a testing tool and a testing system.

[0006] In a first aspect, the present invention provides a method for testing the low-temperature attenuation performance of an optical fiber, the method comprising:

[0007] Winding the optical fiber around an optical fiber low-temperature attenuation performance test disk with a predetermined winding tension, the optical fiber low-temperature attenuation performance test disk comprising a shaft body and baffles arranged on both sides of the shaft body, wherein a buffer material is provided on the shaft body;

[0008] Performing transmission characteristic tests on the wound optical fiber under predetermined test conditions.

[0009] As a preferred embodiment of the method for testing the low-temperature attenuation performance of an optical fiber provided by the present invention, performing transmission characteristic tests on the wound optical fiber under predetermined test conditions includes: placing the wound optical fiber in a low-temperature test chamber and performing low-temperature additional attenuation tests in accordance with the standard of GB / T 15972.52-2008.

[0010] As a preferred embodiment of the method for testing the low-temperature attenuation performance of an optical fiber provided by the present invention, the predetermined winding tension is 10 to 30 g.

[0011] As a preferred embodiment of the method for testing the low-temperature attenuation performance of an optical fiber provided by the present invention, the buffer material is a foam with a foaming rate of 10% to 30%.

[0012] As a preferred embodiment of the method for testing the low - temperature attenuation performance of an optical fiber provided by the present invention, the surface friction coefficient of the optical fiber is 0.15 - 0.75.

[0013] As a preferred embodiment of the method for testing the low - temperature attenuation performance of an optical fiber provided by the present invention, this method is used to test the low - temperature attenuation performance of an optical fiber with a length > 2 km, preferably for testing the low - temperature attenuation performance of an optical fiber with a length >

[0014] 10 km, more preferably for testing the low - temperature attenuation performance of an optical fiber with a length > 30 km, and further preferably for testing the low - temperature attenuation performance of an optical fiber with a length > 60 km.

[0015] As a preferred embodiment of the method for testing the low - temperature attenuation performance of an optical fiber provided by the present invention, this method is used to test the low - temperature attenuation performance of G657 - type optical fibers or G652 - type optical fibers.

[0016] In a second aspect, the present invention provides a test disk for the low - temperature attenuation performance of an optical fiber, which includes a shaft body and baffles arranged on both sides of the shaft body. Among them, a buffer material is provided on the shaft body.

[0017] As a preferred embodiment of the test disk for the low - temperature attenuation performance of an optical fiber provided by the present invention, the buffer material is foam with a foaming rate of 10% - 30%.

[0018] In a third aspect, the present invention provides a test system for the low - temperature attenuation performance of an optical fiber, including:

[0019] A test disk for the low - temperature attenuation performance of an optical fiber, which includes a shaft body and baffles arranged on both sides of the shaft body. Among them, a buffer material is provided on the shaft body;

[0020] A tension - providing device, which is used to provide a preset tension to the optical fiber when winding the optical fiber around the test disk for the low - temperature attenuation performance of an optical fiber.

[0021] As a preferred embodiment of the test system for the low - temperature attenuation performance of an optical fiber provided by the present invention, the buffer material is foam with a foaming rate of 10% - 30%, and the preset winding tension is 10 - 30 g.

[0022] In a fourth aspect, the present invention provides an optical fiber with qualified low - temperature attenuation performance. When the optical fiber is wound around a shaft body provided with a buffer layer, the OTDR graph of the optical fiber measured under predetermined test conditions is a straight line; or, when the optical fiber is wound around a shaft body provided with a buffer layer, the low - temperature attenuation performance measured under predetermined test conditions meets the following conditions:

[0023] When the length of the optical fiber is less than 10 km, the additional attenuation value of the optical fiber is less than 0.2 dB / km;

[0024] When the length of the optical fiber is 10 - 30 km, the additional attenuation value of the optical fiber is less than 0.1 dB / km;

[0025] When the optical fiber length is greater than 30 km, the additional attenuation value of the optical fiber is less than 0.08 dB / km.

[0026] As an optimized solution of the optical fiber with qualified low-temperature attenuation performance provided by the present invention, the buffer material is a foam with a foaming rate of 10% - 30%, and the winding tension of a predetermined size is 10 - 30 g.

[0027] The beneficial effects of the present invention are as follows: The testing method, testing tool and testing system provided by the present invention can perform reliable low-temperature attenuation performance testing on long-distance optical fibers, avoiding the problem of waste caused by truncating the optical fiber to a length of 2 km in the existing national standard testing method; The optical fiber with qualified low-temperature attenuation performance provided by the present invention is qualified for low-temperature attenuation at each point over a relatively long distance, and is suitable for long-distance information transmission in extremely cold or extremely hot areas or areas with extremely large temperature differences between day and night and other harsh environments. Description of the Drawings

[0028] Figure 1 It is a schematic diagram of an optical fiber low-temperature attenuation performance test disc; wherein, 1 is a shaft body. Detailed Embodiments

[0029] The low-temperature attenuation performance of an optical fiber is a key index of the optical fiber. There are many reasons affecting the low-temperature performance of the optical fiber, such as the intrinsic factors of the optical fiber coating, abnormal coating during the drawing and manufacturing process, etc. At present, there are corresponding testing methods for testing the low-temperature attenuation performance of optical fibers. For details, refer to "GB / T15972.52-2008 Optical Fiber Test Method Specification Part 52 Measurement Methods and Test Procedures for Environmental Performance - Temperature Cycling". Place the optical fiber specimen in the test chamber and subject it to temperature changes within a specified period. The test conditions are shown in Table 1:

[0030] Table 1 Test Conditions

[0031]

[0032] This national standard testing method requires that the length of the optical fiber specimen is about 2 km, and the low-temperature attenuation performance test is carried out under the condition of loose winding without tension. It mainly focuses on judging the performance between the coating material and the optical fiber. When the optical fiber is actually produced and applied, there are two major drawbacks to this testing method. On the one hand, this method requires destructive testing, cutting the optical fiber into optical fiber specimens with a length of 2 km for loose winding testing, and it cannot be used in the next process, resulting in a large amount of optical fiber waste; on the other hand, sampling 2 km from a long-distance optical fiber for sampling inspection cannot guarantee that there is no abnormality in the low-temperature attenuation performance of the part of the long-distance optical fiber that has not been sampled.

[0033] For optical fibers used in special fields, especially in fields with extremely high requirements for the low-temperature attenuation performance of optical fibers, it is crucial to ensure the reliable low-temperature attenuation performance of each kilometer of the optical fiber used. Existing commercially available optical fibers are wound around a winding disk with different winding tensions such as 0, 1.0 kg, 1.1 kg, etc. The low-temperature attenuation results directly measured are quite different from the low-temperature attenuation test results of the national standard loose winding of 2 km, making it difficult to accurately measure the low-temperature attenuation value of long-distance optical fibers.

[0034] The applicant found that under the condition of no loose winding, the reason for the large difference between the low-temperature attenuation test results obtained by putting a whole disk of long-distance optical fiber into a low-temperature test chamber and the national standard test results is that during the test process shown in Table 1, the optical fiber experiences 2 cycles of high-temperature and low-temperature alternation, sometimes shrinking due to low temperature and sometimes expanding due to high temperature. When shrinking, the optical fiber and the winding disk press against each other, and when expanding, the optical fibers press against each other, which will affect the transmission characteristics of the optical fiber.

[0035] Based on the above findings, the present invention provides a method for testing the low-temperature attenuation performance of an optical fiber, which includes: winding the optical fiber around a test disk for the low-temperature attenuation performance of the optical fiber with a predetermined winding tension, and testing the transmission characteristics of the wound optical fiber under predetermined test conditions; wherein, the test disk for the low-temperature attenuation performance of the optical fiber includes a shaft body and baffles arranged on both sides of the shaft body. As Figure 1 shown, the present invention sets buffer materials on the shaft body to buffer the pressure exerted by the low-temperature shrinking optical fiber on the winding disk. In this method, the present invention applies a certain winding tension during the winding process of the optical fiber to compensate for the influence caused by the low-temperature shrinkage of the optical fiber.

[0036] This method for testing the low-temperature attenuation performance of the optical fiber can accurately measure the low-temperature attenuation test results close to those of the national standard loose winding of 2 km without shortening the long-distance optical fiber to the national standard length of 2 km, which is accurate and reliable and avoids waste of the optical fiber; compared with the method of sampling the low-temperature attenuation performance of a certain section of the optical fiber by the national standard loose winding of 2 km, the method provided by the present invention can ensure that the low-temperature attenuation performance of each kilometer in the measured long-distance optical fiber is qualified.

[0037] As a preferred scheme of the method for testing the low-temperature attenuation performance of the optical fiber provided by the present invention, testing the transmission characteristics of the wound optical fiber under predetermined test conditions includes: putting the wound optical fiber into a low-temperature test chamber and conducting a low-temperature additional attenuation test in accordance with the standard of GB / T 15972.52-2008. As shown in Table 1, the predetermined test conditions of the present invention include 2 cycles of temperature cycling, with the lowest temperature being -60°C and the highest temperature being 85°C in one temperature cycle.

[0038] The applicant also found that in a whole disk of optical fiber, a certain optical fiber bears three aspects of forces:

[0039] (1) Along the circumferential direction of the shaft body, it is mainly affected by the frictional forces of the left and right optical fibers;

[0040] (2) Along the radial direction of the shaft body, it is mainly affected by the extrusion forces of the upper and lower optical fibers;

[0041] (3) Along the radial direction of the shaft body, the bottom optical fiber is affected by the extrusion force of the shaft body.

[0042] Therefore, based on the above technical solutions, the present invention optimizes the friction coefficient of the optical fiber, the winding tension during the winding process, and the material of the test disc shaft body.

[0043] As a preferred solution of the optical fiber low-temperature attenuation performance test method provided by the present invention, the surface friction coefficient of the optical fiber is 0.15 - 0.75. Controlling the surface friction coefficient can eliminate the additional attenuation caused by the friction of the optical fiber by the left and right optical fibers due to the winding tension.

[0044] As a preferred solution of the optical fiber low-temperature attenuation performance test method provided by the present invention, the winding tension of a predetermined size is 10 - 30 g. The winding tension within this range can keep the optical fiber in a certain free state when the optical fiber shrinks with the low temperature of the test disc shaft body, reducing the influence caused by the extrusion of the upper and lower optical fibers on the optical fiber.

[0045] As a preferred solution of the optical fiber low-temperature attenuation performance test method provided by the present invention, at least the shaft body part of the test disc does not expand and contract thermally under predetermined test conditions; the cushioning material uses foam with a foaming rate of 10% - 30%, which can provide cushioning for the bottom optical fiber, effectively avoiding damage to the optical fiber coating caused by the extrusion of the shaft body on the bottom optical fiber, and eliminating the additional attenuation caused by the mutual extrusion of the upper and lower optical fibers due to the winding tension.

[0046] As a preferred solution of the optical fiber low-temperature attenuation performance test method provided by the present invention, this method is used to test the low-temperature attenuation performance of optical fibers with a length > 2 km, preferably for testing the low-temperature attenuation performance of optical fibers with a length > 10 km, more preferably for testing the low-temperature attenuation performance of optical fibers with a length > 30 km, and further preferably for testing the low-temperature attenuation performance of optical fibers with a length > 60 km.

[0047] The above method is especially suitable for testing the low-temperature attenuation performance of G657 type optical fibers or G652 type optical fibers.

[0048] When testing the low-temperature attenuation performance of the optical fiber by the above method, when the OTDR graph of the optical fiber measured at a predetermined test temperature is a straight line, it is determined that the low-temperature attenuation performance of the optical fiber is qualified.

[0049] When testing the low-temperature attenuation performance of the optical fiber by the above method, when testing G657 type optical fibers, the qualified standard for its low-temperature attenuation performance is as follows:

[0050] When the optical fiber length is less than 10 km, the additional attenuation value of the optical fiber is less than 0.2 dB / km;

[0051] When the optical fiber length is 10 - 30 km, the additional attenuation value of the optical fiber is less than 0.1 dB / km;

[0052] When the optical fiber length is greater than 30 km, the additional attenuation value of the optical fiber is less than 0.08 dB / km.

[0053] In a third aspect, the present invention provides an optical fiber low - temperature attenuation performance test system, including:

[0054] An optical fiber low - temperature attenuation performance test disk, which includes a shaft body and baffles arranged on both sides of the shaft body. Among them, a buffer material is provided on the shaft body;

[0055] A tension providing device, which is used to provide a preset tension to the optical fiber when winding the optical fiber around the optical fiber low - temperature attenuation performance test disk.

[0056] As a preferred solution of the optical fiber low - temperature attenuation performance test system provided by the present invention, the buffer material is a foam with a foaming rate of 10% - 30%, and the preset winding tension is 10 - 30 g.

[0057] In a fourth aspect, the present invention provides an optical fiber with qualified low - temperature attenuation performance. When the optical fiber is wound around a shaft body provided with a buffer layer, the OTDR graph of the optical fiber is a straight line under predetermined test conditions; or, when the optical fiber is wound around a shaft body provided with a buffer layer, the low - temperature attenuation performance measured under predetermined test conditions meets the following conditions:

[0058] When the optical fiber length is less than 10 km, the additional attenuation value of the optical fiber is less than 0.2 dB / km;

[0059] When the optical fiber length is 10 - 30 km, the additional attenuation value of the optical fiber is less than 0.1 dB / km;

[0060] When the optical fiber length is greater than 30 km, the additional attenuation value of the optical fiber is less than 0.08 dB / km.

[0061] As a preferred solution of the optical fiber with qualified low - temperature attenuation performance provided by the present invention, the buffer material is a foam with a foaming rate of 10% - 30%, and the preset winding tension is 10 - 30 g.

[0062] As a preference of the above - mentioned technical solution, the foam can be selected from one or more of polyurethane (PU) foam, expandable polyethylene (EPE) foam, chloroprene rubber (CR) foam, ethylene - vinyl acetate copolymer (EVA) foam, styrene - butadiene rubber (SBR) foam, ethylene - propylene - diene monomer (EPDM) foam.

[0063] In the following embodiments, the present invention discusses the reliability of the low-temperature attenuation performance test of long-distance optical fibers with respect to the winding tension of the optical fiber, the foaming rate of the foam, and the surface friction coefficient of the optical fiber, clarifies the qualification judgment criteria, effectively avoids the misjudgment of unqualified optical fibers due to the differences in test methods, and provides certain guidance for finding problems with unqualified low-temperature attenuation of optical fibers. To ensure that the test results of a whole reel of optical fiber are close to the test results of cutting the whole reel of optical fiber into several 2-kilometer sections in a loose winding state, the present invention needs to particularly control the winding tension of the optical fiber, the foaming requirements of the foam, and the surface friction coefficient of the optical fiber to eliminate the influence caused by the bending of the optical fiber and the mutual extrusion between optical fibers. The present invention is not limited to the specific embodiments and implementation manners described herein. Any person skilled in the art can easily make further improvements and refinements without departing from the spirit and scope of the present invention, and all fall within the protection scope of the present invention.

[0064] Unless otherwise specified, all technical and scientific terms used in the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. Although any methods similar or equivalent to those described herein can be used in the practice or testing of the present invention, the preferred methods will be described herein.

[0065] Unless otherwise specified, the numerical values provided herein should be at most the given endpoints and include the given endpoints.

[0066] The present invention discloses that "loose winding" means that the optical fiber formed with a plurality of optical fiber coils (which can also be called optical fiber turns) is in a natural relaxation state rather than a taut state, and the diameter of the coil needs to be greater than 15 cm.

[0067] The present invention mainly controls the surface friction coefficient within a certain range through two major directions: different types of coatings and coating curing processes.

[0068] In the following embodiments, on a commercially available winding reel (with a winding diameter of 170 mm), the present invention pastes bridge foamed cotton (PE foamed cotton) with different foaming rates and a thickness of 3 mm to form a test reel for the low-temperature attenuation performance of optical fibers, which is used to test the influence of the foaming rate of the buffer material on the accuracy of the test results.

[0069] Example 1

[0070] After the drawing and deuteration of G657 optical fibers are completed, the surface friction coefficient of the cured optical fiber is controlled to be 0.15 through different types of coatings and coating curing processes.

[0071] On the shaft body of the winding reel, paste foam with a foaming rate of 10%, and wind an 8-km optical fiber around the winding reel with a winding tension of 30 g to obtain a reel of optical fiber.

[0072] Take 2 km of G657 optical fiber according to GB / T 15972.52-2008 for diskless loose winding to obtain loose-wound optical fiber.

[0073] Put the spooled optical fiber and the loose-wound optical fiber into a low-temperature test chamber respectively, cool down to -60 °C according to the standard of GB / T15972.52-2008, and after keeping warm for 1 hour, conduct low-temperature additional attenuation test.

[0074] Example 2

[0075] After the drawing and deuteration of G657 optical fiber are completed, control the surface friction coefficient of the cured optical fiber to be 0.15 through different types of coatings and coating curing processes.

[0076] Paste foam with a foaming rate of 30% on the spool shaft body, and wind 18 km of optical fiber on the spool with a spooling tension of 30 g to obtain spooled optical fiber.

[0077] Take 2 km of G657 optical fiber according to GB / T 15972.52-2008 for diskless loose winding to obtain loose-wound optical fiber.

[0078] Put the spooled optical fiber and the loose-wound optical fiber into a low-temperature test chamber respectively, cool down to -60 °C according to the standard of GB / T15972.52-2008, and after keeping warm for 1 hour, conduct low-temperature additional attenuation test.

[0079] Example 3

[0080] After the drawing and deuteration of G652 optical fiber are completed, control the surface friction coefficient of the cured optical fiber to be 0.75 through different types of coatings and coating curing processes.

[0081] Paste foam with a foaming rate of 10% on the spool shaft body, and wind 36 km of optical fiber on the spool with a spooling tension of 60 g to obtain spooled optical fiber.

[0082] Take 2 km of G652 optical fiber according to GB / T 15972.52-2008 for diskless loose winding to obtain loose-wound optical fiber.

[0083] Put the spooled optical fiber and the loose-wound optical fiber into a low-temperature test chamber respectively, cool down to -60 °C according to the standard of GB / T15972.52-2008, and after keeping warm for 1 hour, conduct low-temperature additional attenuation test.

[0084] Example 4

[0085] After the drawing and deuteration of G652 optical fiber are completed, control the surface friction coefficient of the cured optical fiber to be 0.75 through different types of coatings and coating curing processes.

[0086] Paste foam with a foaming rate of 30% on the winding disk shaft body, and wind the optical fiber with a length of 48.8 km on the winding disk with a winding tension of 30 g to obtain a spooled optical fiber.

[0087] Take 2 km of G652 optical fiber according to GB / T 15972.52-2008 for unwinding without a reel to obtain an unwound optical fiber.

[0088] Put the spooled optical fiber and the unwound optical fiber into a low-temperature test chamber respectively, cool down to -60°C according to the standard of GB / T15972.52-2008, keep warm for 1 hour, and then conduct a low-temperature additional attenuation test.

[0089] Comparative Example 1

[0090] After the drawing and deuteration of G657 optical fiber are completed, control the surface friction coefficient of the cured optical fiber to be 0.10 through different types of coatings and coating curing processes.

[0091] Paste foam with a foaming rate of 10% on the winding disk shaft body, and wind the optical fiber with a length of 48.8 km on the winding disk with a winding tension of 30 g to obtain a spooled optical fiber.

[0092] Take 2 km of G657 optical fiber according to GB / T 15972.52-2008 for unwinding without a reel to obtain an unwound optical fiber.

[0093] Put the spooled optical fiber and the unwound optical fiber into a low-temperature test chamber respectively, cool down to -60°C according to the standard of GB / T15972.52-2008, keep warm for 1 hour, and then conduct a low-temperature additional attenuation test.

[0094] Comparative Example 2

[0095] After the drawing and deuteration of G657 optical fiber are completed, control the surface friction coefficient of the cured optical fiber to be 0.80 through different types of coatings and coating curing processes.

[0096] Paste foam with a foaming rate of 10% on the winding disk shaft body, and wind the optical fiber with a length of 48.8 km on the winding disk with a winding tension of 30 g to obtain a spooled optical fiber.

[0097] Take 2 km of G657 optical fiber according to GB / T 15972.52-2008 for unwinding without a reel to obtain an unwound optical fiber.

[0098] Put the spooled optical fiber and the unwound optical fiber into a low-temperature test chamber respectively, cool down to -60°C according to the standard of GB / T15972.52-2008, keep warm for 1 hour, and then conduct a low-temperature additional attenuation test.

[0099] Comparative Example 3

[0100] After the drawing and deuteration of G657 optical fiber are completed, the surface friction coefficient of the cured optical fiber is controlled to be 0.75 through different types of coatings and coating curing processes.

[0101] Paste foam with a foaming rate of 5% on the winding disc shaft body, and wind the optical fiber with a length of 48.8 km around the winding disc with a winding tension of 30 g to obtain a wound optical fiber.

[0102] Take 2 km of G657 optical fiber according to GB / T 15972.52-2008 for unwinding without a disc to obtain an unwound optical fiber.

[0103] Put the wound optical fiber and the unwound optical fiber into a low-temperature test chamber respectively, cool down to -60 °C according to the standard of GB / T15972.52-2008, keep warm for 1 hour, and then conduct a low-temperature additional attenuation test.

[0104] Comparative Example 4

[0105] After the drawing and deuteration of G657 optical fiber are completed, the surface friction coefficient of the cured optical fiber is controlled to be 0.75 through different types of coatings and coating curing processes.

[0106] Paste foam with a foaming rate of 40% on the winding disc, and wind the optical fiber with a length of 48.8 km around the winding disc with a winding tension of 30 g to obtain a wound optical fiber.

[0107] Take 2 km of G657 optical fiber according to GB / T 15972.52-2008 for unwinding without a disc to obtain an unwound optical fiber.

[0108] Put the wound optical fiber and the unwound optical fiber into a low-temperature test chamber respectively, cool down to -60 °C according to the standard of GB / T15972.52-2008, keep warm for 1 hour, and then conduct a low-temperature additional attenuation test.

[0109] Comparative Example 5

[0110] After the drawing and deuteration of G657 optical fiber are completed, the surface friction coefficient of the cured optical fiber is controlled to be 0.75 through different types of coatings and coating curing processes.

[0111] Paste foam with a foaming rate of 10% on the winding disc shaft body, and wind the optical fiber with a length of 48.8 km around the winding disc with a winding tension of 0 g to obtain a wound optical fiber.

[0112] Take 2 km of G657 optical fiber according to GB / T 15972.52-2008 for unwinding without a disc to obtain an unwound optical fiber.

[0113] Put the spooled optical fiber and the loose-wound optical fiber into the low-temperature test chamber respectively, cool down to -60°C according to the standard of GB / T15972.52-2008, and after keeping warm for 1 hour, conduct the low-temperature additional attenuation test.

[0114] Comparative Example 6

[0115] After the drawing and deuteration of G657 optical fiber, control the surface friction coefficient of the cured optical fiber to be 0.75 through different types of coatings and coating curing processes.

[0116] Paste the foam with a foaming rate of 10% on the winding disc shaft body, and wind the optical fiber with a length of 48.8 km on the winding disc with a winding tension of 70 g to obtain the spooled optical fiber.

[0117] Take 2 km of G657 optical fiber according to GB / T 15972.52-2008 for loose winding without a disc to obtain the loose-wound optical fiber.

[0118] Put the spooled optical fiber and the loose-wound optical fiber into the low-temperature test chamber respectively, cool down to -60°C according to the standard of GB / T15972.52-2008, and after keeping warm for 1 hour, conduct the low-temperature additional attenuation test.

[0119] Table 2 Test data of the present invention

[0120]

[0121]

[0122] The national standard stipulates that during the loose-winding test, if the additional attenuation value of the optical fiber < 0.05 dB / km, it is determined that the low-temperature attenuation performance of the optical fiber is qualified.

[0123] Table 2 results show that when the winding tension of a predetermined size is 10 - 30 g, the foaming rate of the buffer material is 10% - 30%, and the surface friction coefficient of the optical fiber is between 0.15 - 0.75, winding the long-distance optical fiber on the optical fiber low-temperature attenuation performance test disc can eliminate the influence caused by the bending of the optical fiber and the mutual extrusion between the optical fibers, making the low-temperature test results of the spooled optical fiber close to the loose-winding test results.

[0124] In summary, the optical fiber low-temperature attenuation performance test method adopted by the present invention can enable the optical fiber to continue to be used in the subsequent process, completely avoiding the problem of optical fiber waste caused by the need to cut the optical fiber to the standard length of 2 km for low-temperature attenuation performance measurement in "GB / T 15972.52-2008 Optical Fiber Test Method Specifications - Part 52: Measurement Methods and Test Procedures for Environmental Performance - Temperature Cycle". It can also ensure that the low-temperature attenuation performance of each kilometer of the long-distance optical fiber is tested, guaranteeing the reliability of the optical fiber in the subsequent process and application. Especially, it provides optical fibers with reliable low-temperature attenuation performance for optical cables used in special fields.

[0125] The above are the preferred embodiments of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and changes can be made, and these improvements and changes are also regarded as the protection scope of the present invention.

Claims

1. A method for testing the low - temperature attenuation performance of an optical fiber, the method comprising: Wrapping the optical fiber around an optical - fiber low - temperature attenuation performance test disk with a winding tension of a predetermined magnitude. The optical - fiber low - temperature attenuation performance test disk includes a shaft body and baffles disposed on both sides of the shaft body. Among them, a buffer material is provided on the shaft body; Conducting transmission characteristic tests on the spooled optical fiber under predetermined test conditions to determine whether the low - temperature attenuation performance of the spooled optical fiber is qualified. The predetermined test conditions include: the winding tension of a predetermined magnitude is 10 - 30 g, the foaming rate of the buffer material is 10% - 30%, and the surface friction coefficient of the optical fiber is 0.15 - 0.

75. The standard for the qualified low - temperature attenuation performance of the spooled optical fiber is: When the optical fiber is wound around the shaft body provided with a buffer layer, the OTDR graph of the optical fiber measured under the predetermined test conditions is a straight line; or, When the optical fiber is wound around the shaft body provided with a buffer layer, the low - temperature attenuation performance measured under the predetermined test conditions meets the following conditions: When the length of the optical fiber is less than 10 km, the additional attenuation value of the optical fiber is less than 0.2 dB / km; When the length of the optical fiber is 10 - 30 km, the additional attenuation value of the optical fiber is less than 0.1 dB / km; When the length of the optical fiber is greater than 30 km, the additional attenuation value of the optical fiber is less than 0.08 dB / km.

2. The method for testing the low-temperature attenuation performance of an optical fiber according to claim 1, characterized in that: The conducting transmission characteristic tests on the spooled optical fiber under the predetermined test conditions includes: Putting the spooled optical fiber into a low - temperature test chamber and conducting low - temperature additional attenuation tests in accordance with the standard of GB / T 15972.52 - 2008.

3. The method for testing the low-temperature attenuation performance of an optical fiber according to claim 1, characterized in that: The buffer material is foam.

4. A fiber optic low-temperature attenuation performance testing system, characterized in that, Including: An optical - fiber low - temperature attenuation performance test disk, which includes a shaft body and baffles disposed on both sides of the shaft body. Among them, a buffer material with a foaming rate of 10% - 30% is provided on the shaft body; A tension - providing device, which is used to provide a winding tension of 10 - 30 g for the optical fiber when winding the optical fiber with a surface friction coefficient of 0.15 - 0.75 around the optical - fiber low - temperature attenuation performance test disk.

5. The optical fiber low-temperature attenuation performance test system according to claim 4, wherein: The buffer material is foam.

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