12 Method E8: Flexing
The purpose of this test is to determine the ability of an optical fibre cable to withstand
repeated flexing in service, e.g. elevator cable.
The sample shall be terminated at each end in a connector, or in a manner such that the fibres,
sheaths and any strain members are clamped together in a representative manner. It shall be
of a length sufficient to carry out the specified test.
The test is carried out using the apparatus shown in Figure 13.
The pulleys shall have a semicircular shaped groove for circular cables and a flat groove for
flat cables. The restraining clamps D shall be fixed so that the pull is always applied by the
weight from which the carriage is moving away. An equivalent apparatus may be used, for
example that shown in IEC 60227-2.
Unless otherwise specified, the conditions for testing shall be in accordance with standard
The sample shall be stretched over the pulleys, each end being loaded with a weight. The
mass of these weights and the diameters of pulleys A and B shall be as specified in the detail
The sample shall be flexed for the number of cycles specified in the detail specification. A cycle
is defined as the movement of the carriage away from its starting position to one end of the
traverse, followed by movement in the opposite direction to the other end and then back to
the starting position.
The acceptance criteria for the test shall be as stated in the detail specification. Typical failure
modes include loss of optical continuity, degradation of optical transmittance or physical
damage to the cable.
12.6 Details to be specified
The detail specification shall include the following:
a) diameters of pulleys A and B;
b) mass of weights;
c) number of cycles.
Flexing Tester for Optical Cables
- Automatic control of full cycle
- Flexing length 1000mm
- Flexing speed 100-350mm/min
- Hammer bracket weight 5kg-2pcs
- Weights 5kg-4pcs,2.5kg-1pcs, 1.0kg-1pcs
- Diameter of wheels 200mm, 250mm, 300mm
- Digital indicator number of cycles
- Adjustment of length of flexing travel
- Chrome coated guide shafts