Laser displacement sensor has been used to measure changes in distance, position, height, width, and thickness of a target object. As it is a non-contact displacement sensor, the laser sensor does not distort, damage or influence the object. Laser sensors can also be easily integrated into already-existing industrial communication systems for automation and monitoring applications. Laser sensors are commonly designed with rugged enclosures without compromising their size. Therefore, they are ideal for measuring in difficult conditions like high-temperature environments or in an area where space is constrained.
Furthermore, laser displacement sensors also offer a wide range of frequency bands to allow measurement of high-frequency applications, such as vibration measurements or quality monitoring in the production line. There are two commonly known types of laser displacement sensors; laser triangulation and time-of-flight sensors. While a triangulation laser sensor is generally more accurate for measuring short distances, a time-of-flight sensor is better suited for the measurement of long distances.
Laser Triangulation Method
A triangulation laser sensor comprises an optical system that includes a metal-oxide-semiconductor (CMOS) detector and a solid-state laser light source. It operates by projecting a beam of light towards the surface of the target object. The focused laser light is incident on the surface of the object being measured. Any movement of the object or any change in the surface properties causes the incident light spot to move along the optical axis of incidence. The scattered light from the point of incidence is imaged on the sensitive surface of a position detector such as a PSD (position sensitive detector) or a CDD (charge-coupled device), resulting in a moving light spot. The projected laser beam is perpendicular to the surface being measured and the optic lens is used to focus the laser beam for an accurate reading.
See the below diagram for a graphical representation.
Time of Flight Principle
Time of flight distance laser sensor measures distance based on the time difference in which the emitted laser beam returns to the sensor after hitting the target objects. This measurement technique offers reliable accuracy for the measurement of large distances or displacements up to several km. The time-of-flight sensors use a transmitter diode to generate a very short pulse of narrow-spectrum red or infrared light which reflects from the target object, pulses and returns to the receiver. The integrated processor calculates the time required for the laser pulse to meet the detection object and returns it to the receiver to output the distance.
We have put together a selection guide for laser triangulation sensors to address your distance and displacement measurement needs in industrial applications.
Putting it all Together!
Laser displacement sensors are commonly used in many industries and research sectors, such as factory process automation, chemical industry, medical, and additive manufacturing for distance, position, dimension and thickness measurement. They work best in confined spaces where it is difficult to use other sensor systems. Selecting the ideal sensor for effective, accurate and reliable displacement measurement requires an understanding of your industrial application needs. So, before making a decision, it is wise to consider various requirements that will help you narrow down the well-suited laser displacement for your industrial applications.
If you face difficulties in making the right selection of displacement measurement applications, contact our engineers at Bestech Australia. We are an authorized partner of Micro-Epsilon in Oceania and provide measurement support for the application of non-contact laser distance measurement sensors for industrial tests and measurement tasks. We can also customize non contact displacement sensors for specialized applications to adapt to the specifications.
