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FAQ03261 of Displacement Sensors / Measurement Sensors FAQ

FAQ No. FAQ03261

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Question

When measuring an object through a window (slit) by using the Optical Type Displacement Sensors, how large should the window be?

Answer



When making a window frame, note the following basic points.

(1) Not intercept the Light Emitting Beam

(2) Not intercept the Light Receiving View

The above points are the essential conditions.

The above points are the essential conditions.

(3) Light should not reflect diffusely on the window frame

If the light reflecting off the object returns to the window frame and enters in the receiving area of the sensor, errors may occur.
Light returns more or less to the window frame depending on how the sensing object inclines or how the light reflects.

Whether or not this reflecting light affects the measurement depends on the amount of diffuse light, reflectance ratio of the window frame, and required measurement accuracy.

It is ideal for the window frame to be made of a material as thin as possible with matte black finish which does not reflect light.

Confirm the dimensions of the window frame, checking the measurement accuracy.