Nano-scale sensors promise extraordinary levels of sensitivity and
selectivity. We can now For years, encoders were the solution to
achieving precise, automated measurement on many industrial machines.
However, in recent years, competition has come from optical sensor
manufacturers, whose devices provide reliable, accurate distance
measurement, particularly in environments not suited to encoders. One
company specialising in this area is Leuze Mayser, which has recently
boosted its portfolio of products this year with models that satisfy a
variety of measuring ranges. The ODLS 8, for example, is suitable for
pile positioning and pile tracking in sheet-fed printing presses. Using a
laser diode as the light source, it measures between 20 and 400mm, with a
resolution of 0.1mm and accuracy of 0.25%. The device has analogue
current and voltage outputs, plus a serial output, simplifying connection
to a variety of control systems. Software is also available for optimum
adjustment of the sensor to the application.
At the other end of the scale is the new laser version of the optical
measuring sensor OMS 2, which is able to measure distances of between
20cm and 170m. The inherent intelligence of this range of optical
distance measurement systems enables measured values to be calculated in
less than 2ms, which is useful for positioning stacker cranes, transfer
cars and other moving equipment. Alignment in these applications is aided
by a visible red light source. Attaching a reflector of 200x200mm extends
the measuring distance to 100m, while longer distances up to 170m are
measured using a larger reflector. Even over these ranges, the OMS series
offers an accuracy of +/-2mm.
For intermediate distances, customers can specify the ODS 30, which has a
maximum range of 30m. This covers applications such as diameter
determination, the positioning of lifting tables, fork positioning for
fork lift trucks and so on. The device is accurate to +/-1mm (depending
on the measuring range), and its switching thresholds and response times
are easily set to meet specific application requirements. Meanwhile, for
shorter distance measurements of up to 5m there is the ODS 96, which
features a CCD element for high measurement accuracy regardless of the
surface properties of the measured object. This device will tolerate
tough ambient conditions, thanks to its metal housing, glass lens cover
and IP67 rating.