IEC 60794-1-22:2012, Optical fibre cables – Part 1-22: Generic specification – Basic optical cable test procedures – Environmental test methods IEC TR 62691, Guide to the installation
Object
This test method evaluates the performance of optical fibre cables under specific tensile strength, focusing on how attenuation and fibre elongation strain respond to the load experienced during installation and operation It is designed to be a non-destructive testing approach.
Sample length
For cables requiring specialized anchoring devices, such as OPGW, all-dielectric self-supporting (ADSS), and heavy wire armored cables, the minimum length under tension is set at 25 m, unless specified otherwise In general, the length under tension should be at least 50 m according to the relevant specifications.
Short lengths in the tensile test will adversely affect the accuracy of the measurement The lengths shown above are the recommended minimum lengths for this test
Total sample length is longer than the length under tension to allow for clamping and connection to test equipment.
Apparatus
The apparatus consists of a) an attenuation measuring apparatus for the determination of attenuation changes
(see IEC 60793-1-40), and/or a fibre elongation strain measuring apparatus
According to IEC 60793_1_22:2001, Method C, a tensile strength measuring apparatus must be capable of accommodating the minimum length required for testing Additionally, transfer devices can be utilized to test longer samples under tension.
The transfer device must have sheave diameters that are at least equal to the minimum bending diameter of the cable being tested, which is usually 1 meter Additionally, a load cell should be used, ensuring a maximum error of ± 3% of its maximum range It is crucial to employ a clamping device to secure all cable components at the ends of the test length, taking care to ensure that the method of securing does not influence the test results A mandrel is often suitable for this purpose, with a typical diameter requirement.
The cable must have a bending diameter of at least 1 meter, adhering to the minimum specifications outlined Additionally, if necessary, mechanical or electrical devices for measuring cable load or elongation should be included as per the detailed specifications.
Examples of suitable apparatus are shown in Figure 1 and Figure 2.
Procedure
General requirements
a) Unless otherwise specified, the conditions for testing shall be in accordance with the expanded test conditions as defined in IEC 60794-1-20
IEC 60794-1-22:2012, Optical fibre cables – Part 1-22: Generic specification – Basic optical cable test procedures – Environmental test methods
IEC TR 62691, Guide to the installation of optical fibre cables
IEC 61300-2-44, Fibre optic interconnecting devices and passive components – Basic test and measurement procedures – Part 2-44: Tests – Flexing of the strain relief of fibre optic devices
This test method evaluates the performance of optical fibre cables under specific tensile strength, focusing on how attenuation and fibre elongation strain respond to the load experienced during installation and operation It is designed to be a non-destructive testing approach.
For cables requiring specialized anchoring devices, such as OPGW, all-dielectric self-supporting (ADSS), and heavy wire armored cables, the minimum length under tension is set at 25 meters In all other cases, the length under tension must be at least 50 meters, unless specified otherwise in the relevant documentation.
Short lengths in the tensile test will adversely affect the accuracy of the measurement The lengths shown above are the recommended minimum lengths for this test
Total sample length is longer than the length under tension to allow for clamping and connection to test equipment
The apparatus consists of a) an attenuation measuring apparatus for the determination of attenuation changes
(see IEC 60793-1-40), and/or a fibre elongation strain measuring apparatus
According to IEC 60793_1_22:2001, Method C, a tensile strength measuring apparatus must be capable of accommodating the minimum length required for testing Additionally, transfer devices can be utilized to test longer samples under tension.
The transfer device must have sheave diameters that are at least equal to the minimum bending diameter of the cable being tested, which is usually 1 meter Additionally, a load cell should be used, ensuring a maximum error of ± 3% of its maximum range It is essential to include a clamping device to secure all cable components at the ends of the test length, taking care to ensure that the method of securing does not influence the results A mandrel is often suitable for this purpose, typically featuring a specific diameter.
The cable must have a minimum bending diameter of 1 meter, adhering to the specified requirements Additionally, if necessary, mechanical or electrical devices for measuring cable load or elongation should be included as per the detailed specifications.
Examples of suitable apparatus are shown in Figure 1 and Figure 2
3.4.1 General requirements a) Unless otherwise specified, the conditions for testing shall be in accordance with the expanded test conditions as defined in IEC 60794-1-20 b) Load the cable onto the tensile rig and secure it At both ends of the tensile rig, a method of securing the cable shall be used, which uniformly locks the cable so that all components of the cable, including fibres, are restricted in their movement For most cable constructions (e.g stranded type cables), clamping on cable elements, except the fibres, is practical and sufficient to obtain attenuation changes and/or both the maximum allowable pulling load and the strain margin of the cable However, for certain cable constructions (e.g single loose tube), it may be necessary to prevent the fibres from slipping in order to obtain the correct strain margin figures
For aerial cable types, the installation may require specific anchoring devices based on the cable type Heavily armoured cables may utilize clamping devices like stocking grips for secure fixing During tensile testing, the test fibre must be connected to the measurement apparatus, ensuring the reference length remains unchanged throughout the process The tension should be gradually increased to the specified values, while monitoring changes in attenuation and fibre strain as a function of cable load or elongation For cables with multiple fibres, a device for measuring multiple attenuations or fibre strains can be employed It is essential to agree on a representative number of fibres and test cycles between the manufacturer and customer Finally, readings must stabilize within measurement uncertainty before altering loads or concluding the test; if fluctuations persist, the load holding period should be extended until stability is achieved.
Procedure
Before initiating the test, it is essential to measure the optical attenuation and determine the fibre strain to establish a baseline First, apply a short-term load to the cable and maintain this load for 10 minutes If necessary, assess the fibre strain Subsequently, if required, adjust the applied load to a long-term load and hold it for another 10 minutes.
– measure the attenuation and/or determine the fibre strain; e) remove the load; f) allow the cable to rest for 5 min; g) measure the attenuation and/or determine the fibre strain
Different steps and load levels can be used if agreed between customer and supplier.
Requirements
The attenuation change and/or fibre strain of the sample shall not exceed the values given in the relevant specification.
Details to be specified
The relevant specification shall include the following:
– length under tension if different from this method;
– T L long term load: load applied, limits on fibre strain, and/or change of attenuation;
– T S short term load: load applied, limits on fibre strain (if required);
– T after the test: limits on fibre strain and/or change in attenuation.
Details to be reported
Values for all attributes from 3.6 shall be reported plus the following:
– temperature, if different from that indicated for standard test conditions
Figure 1 – Tensile performance measuring apparatus
Clamping device Cable length under test
– T L long term load: load applied, limits on fibre strain, and/or change of attenuation;
– T S short term load: load applied, limits on fibre strain (if required);
– T after the test: limits on fibre strain and/or change in attenuation
Values for all attributes from 3.6 shall be reported plus the following:
– temperature, if different from that indicated for standard test conditions
Figure 1 – Tensile performance measuring apparatus
Clamping device Cable length under test
Figure 2 – Example of tensile performance measuring apparatus using transfer devices and chuck drums
Object
The abrasion resistance of optical fibre cables has two aspects: a) the ability of the sheath to resist abrasion, E2A; b) the ability of cable markings to resist abrasion, E2B
The purpose of this test is to determine the ability of an optical fibre cable sheath or sheath markings to resist abrasion.
Sample
The sample shall be of a length sufficient to carry out the specified test A typical length is
Method E2A: Abrasion resistance of optical fibre cable sheaths
Apparatus
The abrasion test rig is engineered to abrade the cable's surface in both directions, parallel to its longitudinal axis, over a length of (40 ± 1) mm.
Chuck drums and transfer device
Transfer deviceTransfer device frequency of (55 ± 5) cycles/min One cycle consists of one abrading edge movement in each direction
The abrading edge shall be a steel needle with a diameter of 1,0 mm or as specified in the detail specification
A typical apparatus is shown in Figure 3.
Procedure
Testing conditions shall adhere to standard atmospheric conditions as outlined in IEC 60794-1-20 The cable sample must be securely attached to the supporting plate using cable clamps, with the abrading edge loaded at 4 N while preventing any shock to the cable The initial position should allow sufficient length for the sample's subsequent movement Four tests will be conducted on the sample, moving it forward by 100 mm between tests and rotating it 90° in the same direction each time.
Requirements
There shall be no perforation of the sheath after performing the number of cycles specified in the detail specification.
Details to be specified
The detail specification shall include the following: a) number of cycles; b) force applied if other than specified herein; and c) diameter of needle if other than specified herein.
Method E2B: Abrasion resistance of optical fibre cable markings
Apparatus
The apparatus is designed in accordance with the specifications outlined in E2A and E2B, Method 1, featuring a wiping felt in place of the needle Key modifications include: a) the introduction of a test setup to exert force on the wool felt, as illustrated in Figure 4; b) the use of a white wool felt.
Common felts are typically made from a blend of wool and other fibers, such as rayon, with wool content ranging from 30% to 100% as specified The testing method requires the application of masses to exert force on the sample, and the apparatus must facilitate a stroke length of 100 mm at a frequency of 6 to 12 cycles per minute, with an optimal frequency of (55 ± 5) cycles per minute Each cycle includes one movement of the abrading edge in both directions.
The abrading edge shall be a steel needle with a diameter of 1,0 mm or as specified in the detail specification
A typical apparatus is shown in Figure 3
Testing conditions shall adhere to standard atmospheric conditions as per IEC 60794-1-20 The cable sample must be securely attached to the supporting plate using cable clamps, with the abrading edge loaded at 4 N while preventing any shock to the cable The initial position should allow for sufficient length for subsequent movements Four tests will be conducted on the sample, moving it forward 100 mm between tests and rotating it 90° in the same direction each time.
There shall be no perforation of the sheath after performing the number of cycles specified in the detail specification
The detail specification shall include the following: a) number of cycles; b) force applied if other than specified herein; and c) diameter of needle if other than specified herein
4.4 Method E2B: Abrasion resistance of optical fibre cable markings
The apparatus is designed in accordance with the specifications outlined in E2A and E2B, Method 1, featuring a wiping felt in place of the needle Key modifications include: a) the introduction of a test setup to exert force on the wool felt, as illustrated in Figure 4; b) the use of white wool felt.
Common felts are typically made from a blend of wool and other fibers, such as rayon, with wool content ranging from 30% to 100% as per specific requirements The testing method involves applying a force to the sample using masses, and the apparatus must accommodate a stroke length of 100 mm at a frequency of 6 to 12 cycles per minute.
Procedure
Unless otherwise specified, the conditions for testing shall be in accordance with standard atmospheric conditions
As specified in E2A, but all four tests shall be made on the cable marking
A cable sample with markings must be positioned between two sections of wool felt or between the wool felt and a supporting surface, ensuring that the wool felt makes contact with the printed area of the cable.
The wool felt shall be thoroughly impregnated with water
The specified normal force of 5 N will be applied to the markings on the sample, which will be moved back and forth over a distance of 100 mm The number of cycles for this movement will be detailed in the specifications.
Requirements
The marking shall be legible at the completion of the test after the number of cycles specified in the detail specification.
Details to be specified
The detail specification shall include the following: a) number of cycles; b) method used; c) force applied if other than specified herein
Figure 3 – Typical test set-up for tests E2A and E2B method 1
Figure 4 – Typical test set-up for test E2B, apparatus 2
Object
The purpose of this test is to determine the ability of an optical fibre cable to withstand crushing for long term and for short-term loads
NOTE Method E3A corresponds to the default method, Method E3 Crush, defined in IEC 60794-1-2:2013.
Sample
The sample shall be of a length sufficient to carry out the specified test.
Method E3A: Plate/plate
Apparatus
The apparatus is designed to crush a cable sample between a flat steel base plate and a movable steel plate, ensuring that the crushing force is applied uniformly across a 100 mm length of the sample.
The movable plate must have its edges rounded to a radius of approximately 5 mm, excluding the 100 mm flat section A suitable apparatus is illustrated in Figure 5.
Procedure
The cable sample must be securely mounted between the plates to prevent lateral movement, and the force should be applied gradually without sudden changes When applying the force in incremental steps, the ratio should not exceed 1.5:1.
Figure 4 – Typical test set-up for test E2B, apparatus 2
The purpose of this test is to determine the ability of an optical fibre cable to withstand crushing for long term and for short-term loads
NOTE Method E3A corresponds to the default method, Method E3 Crush, defined in IEC 60794-1-2:2013
The sample shall be of a length sufficient to carry out the specified test
The apparatus is designed to crush a cable sample between a flat steel base plate and a movable steel plate, ensuring that the crushing force is applied uniformly across a length of 100 mm.
The movable plate should have its edges rounded to a radius of approximately 5 mm, excluding the 100 mm flat section of the plate An appropriate apparatus is illustrated in Figure 5.
The cable sample must be securely mounted between the plates to prevent lateral movement, and the force should be applied gradually without sudden changes When applying the force in incremental steps, the ratio should not exceed 1.5:1.
The force must remain stable at the designated test value for a specified duration, typically 1 minute for short-term tests or 10 minutes for long-term tests, unless otherwise stated in the detailed specifications Prior to releasing the force, attenuation measurements should be conducted.
The test must be conducted three times at different locations on the specimen, without rotating the cable, unless stated otherwise in the detailed specifications Each point of application should be at least 500 mm apart and distinct from the cable core's lay length.
Unless otherwise specified, the conditions for testing shall be in accordance with standard atmospheric conditions.
Method E3B: Mandrel/plate
Apparatus
The same apparatus as for Method E3A shall be used, but a steel mandrel with a diameter of
25 mm (unless otherwise specified in the detail specification) is inserted perpendicular to the sample or replaces the movable plate in Figure 6.
Procedure
The procedure is the same as for Method E3A but a steel mandrel with a diameter of 25 mm (unless otherwise specified in the detail specification) is inserted perpendicular to the sample.
Requirements
The test acceptance criteria will be defined in the detailed specification Common failure modes to consider are the loss of optical continuity, reduced optical transmittance, and physical damage to the cable.
NOTE Imprints or scratches on sheath and cable elements are not regarded as a failure.
Details to be specified
The detailed specifications must encompass the total force applied (F), the duration of force application, the number of tests conducted, the spacing between test locations, the configuration of the mandrel if utilized, and the maximum permissible change in optical transmittance during and after the test for both short- and long-term loads.
R radius of edge of movable plate, 5 mm
F force on movable place, as defined in relevant specification
Figure 5 – Apparatus for crush test, Method E3A, details of plate/plate option
R radius of edge of movable plate, 5 mm
F force on movable place, as defined in relevant specification
Figure 5 – Apparatus for crush test, Method E3A, details of plate/plate option
F force on movable place, as defined in relevant specification
4 mandrel (cylinder or half-cylinder), 25 mm diameter
Figure 6 – Apparatus for crush test, Method E3B, details of plate/mandrel option
Object
The purpose of this test is to determine the ability of an optical fibre cable to withstand impact.
Sample
Sample length
The sample length must be adequate for the required test, typically ranging from 1 m for small diameter jumper cords or duplex cables to 5 m for larger diameter cables For optical measurements, longer lengths may be necessary.
Termination
The sample must be secured at both ends with a connector or in a way that effectively clamps the fibers, sheathings, and strain members together Clamps on the impact apparatus can be utilized, or the sample can be sufficiently long to eliminate the need for additional restraint.
Apparatus
The apparatus is designed to deliver an impact to a cable sample secured to a robust steel base For single or limited impacts, a specific device, illustrated in Figure 7a, is utilized, enabling a weight to drop vertically onto a steel piece that transmits the impact to the cable In cases where multiple impacts are necessary, typically exceeding five, a more efficient apparatus, depicted in Figure 7b, is employed.
L 1 allows multiple impacts by a drop hammer The apparatus shall be arranged to impart minimal friction to the moving weight/hammer.
NOTE This issue of friction has been found to be a particular problem when the apparatus is used at temperature extremes
In both cases, other equivalent apparatus may also be used
The striking surface must be either flat or curved, with a minimum curvature radius of 300 mm When a flat surface is used, the edges should be radiused to prevent stress concentration Alternatively, a striking surface with a 300 mm curvature radius can also be a spherical segment, providing an equivalent testing method to that of a rounded cylinder.
The radius on the edge on the flat striking surface and on the 300 mm curvature radius striking surface shall be approximately 0,5 mm
The apparatus shall include any optical test equipment needed to measure the changes in optical performance as required in the detail specification, and specified in Method A
Procedure
Unless otherwise specified, the conditions for testing shall be in accordance with standard atmospheric conditions
To achieve the specified impact energy, the mass of the weight or drop hammer and the height of its fall must be carefully calibrated Additionally, the detail specification outlines the required number and rate of impacts, as well as their precise locations on the sample.
Requirements
The test acceptance criteria will be defined in the detailed specification Common failure modes to consider are the loss of optical continuity, reduced optical transmittance, and physical damage to the cable.
Details to be specified
The detailed specification must outline the number of impacts, impact energy, test temperature, and the radius of the striking surface if it differs from the specified parameters Additionally, it should include the frequency of multiple impacts, the location of impacts on the sample, and whether optical continuity or changes in transmittance will be measured The setup should permit multiple impacts using a drop hammer while ensuring minimal friction is applied to the moving weight or hammer.
NOTE This issue of friction has been found to be a particular problem when the apparatus is used at temperature extremes
In both cases, other equivalent apparatus may also be used
The striking surface must be either flat or curved, with a minimum curvature radius of 300 mm When a flat surface is used, its edges should be radiused to prevent stress concentration Alternatively, a striking surface with a 300 mm curvature radius can also take the form of a spherical segment, providing an equivalent testing method to that of a rounded cylinder.
The radius on the edge on the flat striking surface and on the 300 mm curvature radius striking surface shall be approximately 0,5 mm
The apparatus shall include any optical test equipment needed to measure the changes in optical performance as required in the detail specification, and specified in Method A
Unless otherwise specified, the conditions for testing shall be in accordance with standard atmospheric conditions
To achieve the specified impact energy, the mass of the weight or drop hammer and the height of its fall must be carefully calibrated Additionally, the detail specification outlines the required number and rate of impacts, as well as their precise locations on the sample.
The test acceptance criteria will be defined in the detailed specification Common failure modes to consider are the loss of optical continuity, reduced optical transmittance, and physical damage to the cable.
The detailed specification must outline the number of impacts, impact energy, test temperature, and the radius of the striking surface if it differs from the specified parameters Additionally, it should include the frequency of multiple impacts, the location of impacts on the sample, and whether optical continuity or changes in transmittance will be measured.
Figure 7a – Impact test – Apparatus for a few impacts
Figure 7b – Impact test – Apparatus for multiple impacts
Steel intermediate striking face Hammer
Drive pinFree running pulley
Figure 7c – Impact test – Details of the striking surface Key d hammer diameter, 20 mm ± 1 mm r striking surface curvature radius, 300 mm, minimum
1 flat striking surface, with radiused edges
7 Method E5A: Stripping force stability of cabled optical fibres
Object
This test determines the stability of the stripping force of the coating of cabled fibres by measuring the change in fibre strippability after exposure to specified environmental conditions.
Sample
Sample length
The length of the cable or fibre sample shall be sufficient to carry out the specified test.
Sample preparation
The cable from which the fibres shall be taken is preconditioned, as specified in the detail specification, prior to withdrawal of the fibres
The test will be conducted on fibers extracted from a cable sample, which is divided into two lengths of at least 2 meters each; one length is designated for testing, while the other is reserved for reference measurements.
To conduct tests on 10 conditioned test pieces of fibre, adequate samples must be provided, allowing for a comparison with test results from fibres extracted from the reference cable length.
After withdrawal, any filling compound adhering to the fibres shall be carefully removed (e.g by wiping with a soft tissue).
Apparatus
The apparatus consists of conditioning equipment (if necessary) and a fibre strippability apparatus (see the strippability test method of IEC 60793-1-32:2010)
Figure 7c – Impact test – Details of the striking surface Key d hammer diameter, 20 mm ± 1 mm r striking surface curvature radius, 300 mm, minimum
1 flat striking surface, with radiused edges
7 Method E5A: Stripping force stability of cabled optical fibres
This test determines the stability of the stripping force of the coating of cabled fibres by measuring the change in fibre strippability after exposure to specified environmental conditions
The length of the cable or fibre sample shall be sufficient to carry out the specified test
The cable from which the fibres shall be taken is preconditioned, as specified in the detail specification, prior to withdrawal of the fibres
The test will be conducted on fibers extracted from a cable sample, which is divided into two lengths of at least 2 meters each; one length will be used for testing while the other will serve for reference measurements.
To ensure accurate testing, adequate samples must be supplied for conducting tests on 10 conditioned test pieces of fibre, as outlined in the detailed specification These results will be compared with those obtained from fibres extracted from the reference cable length.
After withdrawal, any filling compound adhering to the fibres shall be carefully removed (e.g by wiping with a soft tissue)
The apparatus consists of conditioning equipment (if necessary) and a fibre strippability apparatus (see the strippability test method of IEC 60793-1-32:2010)
The strippability of optical fibres will be assessed on environmentally conditioned samples using the IEC 60793-1-32 method, following the specified recovery and reconditioning periods This method will also be applied to fibre samples extracted from the reference cable length, allowing for a comparison of results to determine any changes in stripping force.
Alternatively, samples may be taken from cable aged according to Method F9 of IEC 60794-1- 22:2012
The change in stripping force shall meet the requirements specified in the detail specification
The detail specification shall include the following: a) cable preconditioning; b) fibre conditioning; c) recovery time and reconditioning; d) permissible change in stripping force
8 Method E5B: Strippability of optical fibre ribbons
The purpose of this test is to evaluate the strippability of optical fibre ribbons in terms of fibre cleanliness after coating removal and fibre breakage due to ribbon stripping
The test sample shall be representative of the population of ribbons under evaluation
Samples may be taken sequentially along a length of ribbon but sections of the ribbon previously in the grips of the stripping tool shall be excluded
The sample length must be adequate to enable the removal of matrix and fiber coatings over a minimum length of 25 mm, with each sample containing between five to ten strips.
Sample environmental conditioning requirements shall be agreed between customer and supplier
A ribbon stripping apparatus and conditioning equipment (if necessary)
The results of the test are strongly dependent upon the design of the stripping tool used and the following tool design guidelines shall be taken into account:
The mechanical stripping tool must feature a heated surface that operates between +70 °C and +140 °C It is essential that this heated surface maintains the specified temperature within a tolerance of ± 5 °C throughout the stripping process.
The heated surface(s) shall be located behind the stripping blades and positioned to heat the part of the ribbon in which the coating is to be removed
Heat-up time and dwell time for the tool may be important and the tool manufacturers recommendations shall be followed
Follow the ribbon manufacturer’s recommendations for setting the tool temperature
– The stripping tool or loading fixture shall maintain a constant pressure sufficient for proper stripping Care shall be taken that the tool does not begin to open during stripping
The gap size between the blades must be precisely defined, with specific tolerances, to guarantee that the blades effectively cut through the matrix material and fiber coatings while preventing any damage to the fiber cladding.
The condition of the blades significantly influences the peak strip force and the effectiveness of the stripping action It is essential to inspect the edges of the blades for notches and burrs both before and after use to ensure optimal performance.
– Replace the blades when they become damaged or blunt or whenever wear is sufficient to affect the results
8.3.3 Motor and slide (if used)
The motor and slide shall allow repeatable motion with low vibration and fast acceleration
They shall be capable of imparting constant motion, without jerking, to the test ribbon or stripping tool
If a manual tool is used, the stripping action shall follow these same criteria
To ensure accurate testing, the sample must be securely held to prevent any slippage, with a capstan being a recommended tool Additionally, the ribbon fibers of the sample should be aligned vertically, horizontally, and rotationally with the direction of the stripping motion.
A non-abrasive cloth or paper material saturated with a suitable alcohol solution shall be used to wipe the fibres after stripping
Testing conditions must adhere to controlled ambient standards unless stated otherwise The strip length should be a minimum of 25 mm, and the strip velocity must align with the detailed specifications, ranging from 100 mm/min to 500 mm/min.
Turn on the test apparatus and allow the tool temperature to stabilize
Ensure that the area around both blades of the stripping tool is free from debris from any previous use and that the blades are clean
Strip the ribbon following the manufacturer’s recommendation on heating dwell time prior to stripping
After stripping wipe the stripped fibres with the alcohol wipe and inspect them visually at a magnification of at least 2X
Assess the cleanliness and integrity of the fibres after stripping as indicated in Table 1 temperature, shall maintain that temperature within ± 5 °C during the stripping operation
The heated surface(s) shall be located behind the stripping blades and positioned to heat the part of the ribbon in which the coating is to be removed
Heat-up time and dwell time for the tool may be important and the tool manufacturers recommendations shall be followed
Follow the ribbon manufacturer’s recommendations for setting the tool temperature
– The stripping tool or loading fixture shall maintain a constant pressure sufficient for proper stripping Care shall be taken that the tool does not begin to open during stripping
The gap size between the blades must be precisely determined, with specific tolerances, to ensure effective cutting of the matrix material and fiber coatings while preventing any damage to the fiber cladding.
The condition of the blades significantly influences the peak strip force and the effectiveness of the stripping action It is essential to inspect the edges of the blades for notches and burrs both before and after use to ensure optimal performance.
– Replace the blades when they become damaged or blunt or whenever wear is sufficient to affect the results
8.3.3 Motor and slide (if used)
The motor and slide shall allow repeatable motion with low vibration and fast acceleration
They shall be capable of imparting constant motion, without jerking, to the test ribbon or stripping tool
If a manual tool is used, the stripping action shall follow these same criteria
To ensure accurate testing, the sample must be securely held to prevent any slippage, with a capstan being a recommended tool Additionally, the ribbon fibers of the sample should be aligned vertically, horizontally, and rotationally with the direction of the stripping motion.
A non-abrasive cloth or paper material saturated with a suitable alcohol solution shall be used to wipe the fibres after stripping
Testing conditions must adhere to controlled ambient standards unless stated otherwise The strip length should be a minimum of 25 mm, and the strip velocity must align with the detailed specifications, ranging from 100 mm/min to 500 mm/min.
Turn on the test apparatus and allow the tool temperature to stabilize
Ensure that the area around both blades of the stripping tool is free from debris from any previous use and that the blades are clean
Strip the ribbon following the manufacturer’s recommendation on heating dwell time prior to stripping
After stripping wipe the stripped fibres with the alcohol wipe and inspect them visually at a magnification of at least 2X
Assess the cleanliness and integrity of the fibres after stripping as indicated in Table 1
Table 1 – Condition of stripped samples
Rating Condition of stripped sample
1 Coating and matrix materials leave no residue after one or two alcohol wipe
Coating and matrix materials can crumble or break apart, resulting in a significant residue during the stripping process This often necessitates the use of multiple alcohol wipes to effectively clean the fibers However, the fibers can be wiped clean without the need for a second stripping.
3 Incomplete strip, some fibre coating remains intact Multiple strips and alcohol wipes are required to remove all visible residue from the fibres
– One or more fibres break
– Fail to strip within the required speed
Carry out the number of strips as given in the detail specification and calculate the average cleanliness rating for each sample, rounded to the nearest whole number
The average cleanliness rating shall comply with the values given in the detail specification
The detailed specification must encompass the type of stripping apparatus, average dwell time, stripping tool temperature, stripping velocity, strip length, sample environmental conditioning, required average cleanliness rating, and the number of fibers in the ribbon.
9 Method E5C: Strippability of buffered optical fibres
This test determines the stability of the stripping force of buffered optical fibres