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antenna for such strong magnetic fields and saturates the resonant oscillator circuit. © Festo Didactic GmbH & Co. KG • FP 1110 229 15. Special designs and variants of proximity sensors By using a special core material for the oscillator coil and an electronic circuit which
recognises the presence of a welding field and blocks the switch output during the
short welding pulse, it is possible to use these sensors in welding lines such as in
the automotive industry. Just how large these magnetic fields are, can for instance
be seen by the fact that a steel wrist watch at a distance of approximately 30 cm
from the current-carrying conductor is easily attracted by this. Examples • Sizes M 12 x 1, M 18 x 1 and M 30 x 1.5 with switching distances of 2 mm, 5 mm
and 10 mm. These proximity sensors are magnetic field proof in continuous and
alternating fields with magnetic currents of up to 25 kA. A Teflon protective
screwed cover is available for the protection of active surface against welding
• Magnetic field proof indu...
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