The ToF method is based on the pulse transit time measurement of light. Light is emitted by a transmitter and reflected by one or more objects. The reflected light beams are detected by a receiver and the distance is then determined.

ToF technology is generally considered to be comparatively robust against false alarms. Another advantage of the ToF method is its insensitivity to colors. "Whether you approach the sensor with white, red or black gloves - this has no effect on the detection," explains Anette Riedl-Materna, Product Manager at Schurter. "The signal is always converted with the same speed and precision."

Because they have no moving parts, non-contact optical sensors based on ToF are very reliable. Thanks to their enclosed design and the associated high IP protection, they can usually be used outdoors without any problems.

The optical switches in the TTS series, which are based on ToF technology, can be programmed individually and precisely, which prevents malfunctions. In principle, they are programmed so that the detection distance is 0.05 to 60 mm as standard. This ensures that wiping over or cleaning the switch surface does not trigger a switching signal. Because they have no moving parts, the switches achieve a service life of more than 20 million switching cycles. Visual feedback is provided by a two-color ring illumination (red/green) in the actuator, whose supply voltage is between 5 and 28 V DC. The push-buttons are fixed in place with a nut and have an anti-twist protection so that they can be easily replaced. They can be used in a variety of ways - in public areas, for example, they are suitable for vending machines, parking systems or sanitary areas to prevent contact. The detection distance can also be set so that the switches can be used as light barriers for certain applications, thus opening up a new field of application.