Ultrasonic sensors and reflective photoelectric sensors are both non-contact measurement instruments.

　　Generally speaking, the differences between ultrasonic sensors and reflective photoelectric sensors are mainly in the following areas:

I. Working principle

　　1, ultrasonic sensor: is the ultrasonic signal into other energy signals (usually electrical signals) of the sensor. Ultrasonic waves are mechanical waves that vibrate at frequencies higher than 20kHz.

　　2, reflective photoelectric sensor: is the transmitter and receiver into the same device, installed in front of a reflective plate, the use of reflection principle to complete the role of photoelectric control photoelectric sensor. Can be used to detect changes in ground light and dark and colour, but also to detect the presence of approaching objects.

　　Second, product characteristics

　　1, ultrasonic sensor: it has a high frequency, short wavelength, around the phenomenon of small, especially good direction, can become a ray and directional propagation and other characteristics. Ultrasonic wave on the liquid, solid penetration ability is great, especially in the sun opaque solid. Ultrasound encounters impurities or interface will produce significant reflection of the formation of reflected echo, encounter active objects can produce Doppler effect.

2、Reflective photoelectric sensor

　　It is easy to install and wire, easy to align the light path when installing and using, not affected by the shape, colour and material of the object being inspected, and saves installation space compared to the reflective photoelectric sensor.

　　Three, product applications

　　1、Ultrasonic sensors: widely used in industry, national defence, biomedicine, etc.

　　2、Reflective photoelectric sensors: widely used in money counting machines, limit switches, counters, motor speed measurement, printers, copiers, liquid level switches, financial equipment, entertainment equipment (automatic mahjong machines), stage lighting control, monitoring head control, motion direction discrimination, counting, electric winding machine counting, power meter rotation measurement.

　　Four, other differences

　　Other specific differences between ultrasonic sensors and reflective photoelectric sensors are shown in the following table: