Explain the concept of Photomicrosensors’ lifetime.

LED degradation determines the lifetime of Photomicrosensors (photointerrupters). Sensor lifetime is estimated from the amount of light under continuous current operation of the LED. According to the graph, the lifetime of this Photomicrosensors is 10 years. To estimate the lifetime of Photomicrosensors in order to design a device/equipment, refer to “Technical Explanation of Photomicrosensors.”

Photomicrosensors (phototransistor output) detect objects by comparing S/N ratio (when there is an object or no object). The lifetime of Photomicrosensors depends on the S/N ratio and the threshold level during operation. For example, for transmissive (aperture) Photomicrosensors where the threshold level is set at 30% of the minimum value of the light current, the Photomicrosensors will continue operating until the amount of the light emissions decline to 30% from the initial value (In this case, the lowest-sensitivity Photomicrosensors are used). It is recommended that the device/equipment design should be optimized in order to ensure the dynamic range of S/N. This will lengthen the Photomicrosensors’s lifetime.