What is an effective aperture angle (directional angle)?

The effective aperture angle is the angle where the control output changes from ON (see note) to OFF when a Safety Sensor/Safety Light Curtain is rotated.
The angle is measured against the rotation around the optical axis center line and the pivot rotation direction.

Note: Control outputs for OMRON Safety Sensors/Safety Light Curtains are always ON when light is incident.

Example: When Using an F3SN-A Series Safety Light Curtains

F3SN-A Series effective aperture angle (directional angle) listed in the catalog specifications is within ±2.5° when the sensing distance for the emitter and receiver is at least 3m. This means that the effective aperture angle when the control output changes from ON to OFF when the optical center line is used as the axis of rotation (fig. 1) or the pivot point is used as the axis of rotation (fig. 2) is within ±2.5°.

Fig. 1 Using the Optical Axis Center Line as the Axis of Rotation

Fig. 2 Using the Pivot Point as the Axis of Rotation