Displacement sensors are used to measure changes in displacement and position of target objects. They are available in many different technologies to suit applications in different operating conditions. Displacement sensors can be broadly classified into two categories: those that require physical contact with the object or system being monitored (contact sensors), and those that don’t (non-contact sensors).
Non-contact displacement sensors are available in a variety of shapes, sizes, and measurement methods to serve specific measurement needs in different environments and object types, from laser triangulation, confocal, eddy current, capacitive, and many more. In particular, laser displacement sensors are increasingly used due to their versatility for measurement in a wide range of conditions, including measurement in space-restricted environments, highly-sensitive surfaces or production environments.
There are currently two different sensing technology for laser displacement sensors; the triangulation-based principle and the time-of-flight principle. Laser triangulation sensors measure the change in displacement based on the light reflected from the object to the optics, based on the triangulation principle. This technique allows for measuring small changes down to micrometre resolution. On the other hand, a time-of-flight laser measure distance based on the time taken for a light beam to travel to an object and back. Time-of-flight lasers are generally used for measuring large distances and are suitable for applications in an outdoor environment.
You can read the detailed working principle of laser displacement sensors here.
Laser displacement sensors offer advantages for industrial testing and measurement as they can measure from a large stand-off distance with extremely high accuracy and a fast-measuring rate. As such, these lasers have been used for quality control and automation task in a dynamic environment such as a production line in a manufacturing environment or industrial research applications.
For example, non-contact laser sensors are used for quality control in the metal processing industry to measure the ring diameter in the rolling mill. This application involves operations at a high temperature of up to 1100°C to process materials such as stainless steel and titanium and roll them into large rings via the forming process. The rolling process causes the ring’s diameter to increase continuously. Because only minimal tolerances are allowed, the rolling process must be continuously monitored and the diameter must be precisely measured.
Laser sensors can be mounted from a safe distance to precisely measure the diameter of the roll, which is difficult to be achieved via conventional measurement techniques or contact-type displacement sensors. In fact, blue laser displacement sensors are ideal for this measurement application as they are specifically designed for high-temperature metal processing applications due to their patented blue laser technology. This configuration also minimizes the risk of workplace injury and maximize the lifetime of the sensors as the measurement are conducted from safe distances.
For quality control and manufacturing, non-contact laser displacement sensors offer cost-effective solutions due to their capability to easily communicate and interface with almost any industrial interface, such as analogue, RS422, EtherNET, EtherCAT, etc. Engineers will find it easier to integrate these sensors in their measurement systems such as measuring the thickness of plasterboard or sheet metals, measuring levels of bulk materials and sorting manufacturing defects.
The rise in automation technologies has provided engineers with a wide range of advanced sensors and measuring instruments for improving their processes and developing new measurement systems. Due to their adaptability, laser displacement sensors have been used in a wide variety of industrial test and measurement applications, including monitoring the structural health of buildings, civil engineering, factory automation, manufacturing automation, and research and development for the mining and defence industries.
Choosing the suitable displacement sensor for the specific industrial application is challenging. This is where we can help. At Bestech Australia, our engineers offer technical expertise in industrial test and measurement applications. We are an authorized partner of Micro-Epsilon in Oceania and we provide full measurement support for the application of non-contact laser displacement sensors. We provide not only suitable sensors but also support you in designing special and custom systems to adapt to your specific requirement.
