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FAQ00313 of Photoelectric Sensors FAQ

FAQ No. FAQ00313

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Question

When using a Fiber Unit mounted to a movable part, are there models that are less affected by repetitive bending?

Answer



Seven models are recommended: E32-T11 Fiber Unit, E32-T21, E32-T22B, E32-D11, E32-D21, E32-D21B, and E32-D22B. (These have a bending radius of R4.)

Explanation:

The allowable bending radius of most Fiber Units is 25 mm minimum. Only the seven models listed above have an allowable bending radius of 4 mm. The fiber flexing characteristics have a strong relationship with the bare fiber diameter (see note 1). A bending radius that is 3 times or less the diameter exerts excessive force on the fiber and reduces the optical characteristics (see note 2 on light intensity).

ModelBare fiber diameterFlexing resistance data (light intensity retention, see note 3)
E32-T11
E32-D11
16 x 0.265 dia.Value after flexing 1,000 times at a bending radius of 4 mm (with no
change)/Value after flexing 1,000,000 times (approx. 80%)
E32-T21
E32-T22B
E32-D21
E32-D21B
E32-D22B
4 x 0.25 dia.Value after flexing 1,000 times at a bending radius of 4 mm (with no
change)/Value after flexing 1,000,000 times (approx. 85%)
E32-TC200
E32-DC200
1 x 1 dia.Value after flexing 1,000 times at a bending radius of 5 mm (approx. 95%)

Note:

1.Flexible Fiber Units (E32-[][]R) have an allowable bending radius of 1 mm, but do not handle repetitive bending well, so they should not be mounted on movable parts.

2.The light intensity of a Through-beam model is reduced to 50%, which reduces the sensing distance by about 30%.

3.

The Fiber Units listed above have a structure that strongly withstands the bending radius R by using fibers with ultra-small diameters.

Note:Flexible Fiber Units (E32-[][]R) have an allowable bending radius of 1 mm, but do not handle repetitive bending well, so they should not be mounted on movable parts.