Information on the most widely used ASTM standards within the materials testing industry
Model: UTOF35-RB, IEC 60794-1-21 Method E6: Repeat Bend Test
UTOF35-RB Optical Fiber Cable Repeat Bending Testing Machine is suitable for testing the ability of optical cables to withstand repeated bending. By applying repeated bending forces, qualified optical cables are required to have no fiber breakage, the change in fiber attenuation should not exceed the value specified in the detailed specifications of the optical cable product, and the cable sheath should not crack. Compliant with IEC 60794-1-E6 Repeated Bending Test.
General introduction
UTOF35-RB Optical Fiber Cable Repeat Bending Testing Machine is suitable for testing the ability of optical cables to withstand repeated bending. By applying repeated bending forces, qualified optical cables are required to have no fiber breakage, the change in fiber attenuation should not exceed the value specified in the detailed specifications of the optical cable product, and the cable sheath should not crack. Compliant with IEC 60794-1-E6 Repeated Bending Test.
Sample Length:
The sample length shall be sufficient to carry out the specified test. When only physical damage is to be evaluated the length may range from 1 m (for example for small diameter cords or duplex cables) to 5 m (for larger diameter cables). Longer lengths may be necessary to permit optical measurements.
The sample shall be terminated at each end in a manner such that the fibres, sheathings and any strain members are clamped together in a representative manner. The clamps on the bending apparatus may be adequate, a connector may be used or the sample may be long enough that no restraint is needed.
Acceptance criteria:
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.
The detail specification shall include the following:
a) number of cycles;
b) mass of the weight tensile load, if applicable;
c) bending radius R, if different to that already specified;
d) specific temperature if other than standard atmospheric conditions;
e) maximum allowable change in optical transmittance, during and after the test if required.
Key Features
This equipment uses a human-machine interface and PLC control, with a TFT true-color screen to display test parameters and experimental data. The position of the optical cable on the swinging arm is adjustable, and it can be equipped with different weights and bending rollers with various bending radii. It can meet the requirements for repeated bending tests of butterfly entry optical cables and other optical cables for access networks. The speed is stepless adjustment, with an attractive design, stable performance, simple operation, and safe use.
IEC 60794-1-21 Optical fibre cables - Part 1-21: Generic specification - Basic optical cable test procedures - Mechanical tests methods
IEC 60794-1-21 Method E6: Repeat Bend Test
EN 60794-1 Optical fibre cables - Part 1: Generic specification - Basic optical cable test procedures
GB/T 7424.21: Optical fibre cable generic specification - Part 21:Basic optical cable test procedures- Mechanical test methods
a) precondition the sample at standard atmospheric conditions for 24 h;
b) fix the sample to the apparatus, as such shown in Figure 8;
c) apply the load, as required by the detail specification;
d) measure acceptance criteria parameters to establish baseline values;
e) carry out the number of cycles of repeated bending specified;
f) carry out acceptance criteria parameter measurements. If necessary, the sample may be removed from the apparatus for visual examination.

Main technical specification
| Repeated bending angle | ±90° |
| Repeated bending speed | (10–35) times/minute, adjustable |
| Number of repeated bends | 1–99,999, adjustable |
| Suitable for cable diameters | 5-8mm, 8-15mm, 15-20mm |
| Weight bracket | 5kg |
| Weights | 5kgx4, 2.5kgx1, 1.0 kgx1 |
| Bending wheel diameters | 50mm, 75mm, 100mm, 150mm |
| Distance from the fiber optic cable clamp to the pulley cutting point | 250mm, 500mm, 1000mm (adjustable). The test can be started independently by the machine or remotely controlled by a computer. The number of bending cycles is recorded automatically, and the test stops automatically when finished. |
| Weight | 600kg |
| The test can be started independently by the machine or remotely controlled by a computer. | |
| The number of bending cycles is recorded automatically, and the test stops automatically when finished. | |
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