Electricity + Control September 2015

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ROUND UP
Retro-reflective sensors – no need for manual alignment
The calibrated abeam optics on the Leuze
PRK 18B Series sensors ensure precise
striking of even the smallest reflectors,
eliminating the need for time consuming
alignment after mounting. With a host of
new features, the innovative sensor can
reliably detect small, thin and transparent
objects, such as foils, even under extreme
environmental conditions.
Gerry Bryant, managing director of sole
SouthernAfrican distributor for Leuze sens-
ing equipment – Countapulse Controls,
says that these compact sensors have a
shorter response time, higher switching
frequency, improved adjustability of the
switching point and a tracking function for
extending the cleaning interval.
Leuze abeam technology includes an auto-
collimated lens which is up to eight times
more precise than standard optics.
With a maximum deviation of ±0,25 %,
the light beam has a deviation of only
±2,2 mm over a distance of 500 mm.
“When compared to a two lens system,
these auto-collimated sensors have only
one optical channel, thereby eliminating
angle errors and removing restrictions with
regard to their fitting position. This makes
them the ideal choice for detection of ob-
jects at short ranges,” Bryant points out.
The elimination of an additional front
screen prevents reflections and reduces
drop formation for a more accurate sens-
ing capability. Accuracy and reliability of
detection is further ensured through the
compensation for temperature fluctuations
of ±20 °C.
The Leuze PRK 18B has a switching
frequency of up to 5 000 Hz, a response
time of 100 µs that makes it considerably
faster than comparative sensors at dynamic
transport speeds and a jitter time of 32 µs,
resulting in increased accuracy at static
transport speeds.
The M4 internal threads of the Leuze PRK
18B sensor are integrated into the highly
robust housing, reducing materials by 80 %
and resulting in faster, uncomplicated initial
mounting and subsequent device changes.
Enquiries: Gerry Bryant.Tel. 011 615 7556 or
email
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