FAQ00428 of Photoelectric Sensors FAQ

Even if the light of a emitter is received, the sensor is the light shielding, or even if the light of a emitter is intercepted, the sensor is light entering, when direct sunlight enter the receiver.
Therefore, please use the ambient illuminance by the sunlight 10,000 lx max as described to ratings/characteristics of the catalog.

Photoelectric sensors emit light by pulse and it turns on/off by level of the amount of light received.

The sunlight deletes the received light signal of the emitter and the sensor is the light shielding when direct sunlight strikes to receiver.
Additionally, even if the light of an emitter is intercepted, direct sunlight is considered as receiving signal and the sensor is light entering.
Therefore, please use the ambient illuminance by the sunlight 10,000 lx max.*

* The Value of the illuminance is approx. 10,000 lx max in shade. This value is changed the sunlight power. So, the value is just for your reference.