Datasheet

The principle by which ultrasonic sensors yield measurements is that
evaluating the time taken for the sound to travel between transmission
and reception (direct detection), or a process of checking whether the
transmitted signal has been received (reflex mode).
Reflex mode Direct detection mode
Through-beam sensor
The emitter and the receiver are mounted
facing each other. If the ultrasonic beam is
broken by an object, then the switch output
becomes active.
Advantage: High sensing range
Reflex sensor
The emitter and receiver are mounted in the same
housing. The ultrasonic beam is reflected back to
the receiver by a fixed reflector plate.
Advantage: Reliable detection of not or poorly
reflecting objects.
The object acts as a sound reflector.
Direct detection type
The emitter and receiver are
mounted in the same housing
(reflex sensor).
Advantage: Simple and compact sensor
most frequently used
principle
Direct detection type
The emitter and receiver are separate,
the axes of the emitter and receiver
ultrasonic transducers intersect each
other (reflex/direct detection).
Advantage: It is possible to detect
very small objects.
The following distinc-
tions are made between
types of sensor function:
Object
Object
Object
Object
Fixed reflector
Switch output
Switch output
Switch output
Switch output
Ultrasonic
sensor
Ultrasonic
receiver
Ultrasonic
emitter
Ultrasonic
receiver
Ultrasonic
emitter
Ultrasonic
emitter
Ultrasonic
receiver
Ultrasonic
receiver
Ultrasonic Sensors
Functions
3