Posted to News on 27th Mar 2008, 20:08
Low-cost laser sensors detect small parts at long distances
Contrinex is introducing a new range of M18, low-cost, high-precision diffuse laser sensors designed for detecting small components or features during manufacturing processes.
This type of detection has long posed difficulties for manufacturing engineers, who have to resort to using compact, focussed-beam sensors or accurately-set miniature fibre optics. However, both these methods require the sensors to be situated close to the target and, in many applications, there is insufficient space to implement these arrangements. As a result, vision systems are sometimes the only practical alternative but such systems are highly expensive and require a high level of application knowledge for reliable deployment.
The new Contrinex sensors use a new generation of low-cost, precision diffuse lasers in which the beam spot can be reduced to just 0.2mm diameter by use of an adjustable iris. This enables them to detect objects as small as 0.1mm diameter at a distance of 150mm, making them useful for detecting small objects or features. The operating distance can be extended by a geared multi-turn potentiometer to 600mm and, even at this distance, targets of 0.6mm diameter can be detected.
Easy set-up
A 660nm visible red laser beam makes alignment and set-up very easy and the sensor has very high immunity to interference from other bright light sources such as arcs or direct sunlight. To ensure the highest levels of reliability, Contrinex has included a diagnostic feature that continuously tracks the received light. If the light level falls due to dirt accumulation or misalignment, the diagnostic "excess light' function output is triggered, alerting the user to check the set-up before the principle output fails, thereby reducing expensive unplanned stoppages.
These new M18 laser sensors have an operating frequency of 5000Hz and this short response time ensures that even small components do not escape detection. Sealed to IP67, they are supplied in a body length of only 50mm and are made from tough stainless steel.
The sensors have a wide operating supply voltage from 10-30V DC, a switched current rating of 200mA and a stable sensing range from -25 to +55degC. They are also short-circuit and inverse-polarity proof, and overload protected.
