Contrast is the difference in opposites, such as black and white. In photoelectric sensors, contrast means the difference either in brightness between two objects or in multiple colors on an object. As a result, the larger the difference, the higher the contrast.
Contrast sensors with switching or analog output measure the brightness of objects. Sensors with switching output compare the brightness level with a reference value in order to recognize contrast.
Sensors with analog output provide the measured brightness as a proportional voltage signal in order to monitor brightness curves.
- Detecting text, numbers and barcodes
- Detecting print marks
- Detecting edges