CMMs detect the geometrical properties of workpieces . Optical sensors offer many advantages over tactile measurement technology , as measurements are reactionless , high resolution and fast .
Advantages of optical sensors in coordinate measuring machines
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Coordinate measuring machines are used for high precision quality and parts inspection . Optical distance sensors are increasingly being used for this purpose to replace conventional mechanical gauges . There are numerous reasons for using non-contact sensors : the measurement is reactionless , fast and offers high resolution . Modern optical sensors such as laser triangulation sensors , laser scanners and confocal sensors are particularly suitable for this purpose , says Glenn Wedgbrow , Business Development Manager at Micro-Epsilon UK .
Coordinate measuring machines ( CMMs ) detect the geometrical properties of workpieces in detail . For many years , measuring systems were equipped with tactile sensors , but these are increasingly being replaced by optical sensors . Optical sensors offer numerous advantages over tactile measurement technology . Laser triangulation sensors , laser scanners and confocal chromatic sensors measure the target without making contact . This means that the sensors do not have any influence on the measuring object . The measurements are performed with micrometer accuracy and are normally faster than contact measurement methods .
In practical use , optical sensors are extremely flexible . They measure distance , dimensions , position , angles , shape , roughness and even 3D profiles . Micro-Epsilon offers a broad sensor portfolio that has proven itself in numerous measuring machines . The sensors are used in various systems for both measurement and precise positioning .
Fine positioning with laser triangulation sensors
For positioning of the measuring head , optoNCDT 1900 laser triangulation sensors measure the distance to the target or baseplate . This type of sensor is particularly suitable for precise distance control and object detection . This allows the CMM ’ s geometry data acquisition systems to be aligned with maximum precision . The laser sensors are integrated into the measuring head system , which is typically attached to the vertical z-axis – the quill . The laser sensor delivers maximum signal stability and due to its compact design , is easy to integrate . The lightweight , robust laser sensor makes it ideal for measurements with high accelerations . The sensor operates at measuring rates of up to 10 kHz and offers a linearity of ± 1 µ m and a repeatability of 0.1 µ m .