Preliminary Device Description HG G-19600ZA | English, Revision 02 | Date: 13.03.2018
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Mounting – Chapter 3
3.2 Magnet Sensor
3.2.1 Requirements
ATTENTION!
Additional magnetic fields close to the magnet sensor can affect the system characteristics!
External magnetic fields with a field strength below the Earth‘s magnetic field do not influ-
ence the magnet sensor. For stronger fields the strength and position of the field determine
whether the magnet sensor is affected or can even be configured to compensate the influ-
ence. Fields that asymmetrically influence from a certain direction (left or right) or only oc-
cur at certain points of the course are harder to compensate. Generally interferences should
be minimized so that the magnet sensor can detect the track reliably. Therefore:
Figure 5
Areas around sensor and tape that need to be free of ferromagnetic materials
–
An area of 100 mm around the sensor should be free of ferromagnetic materials.
Those divert the magnetic field and distort the readings. Similarly an area with a
diameter of approximately the nominal reading height around the magnetic tape
should be free of ferromagnetic materials.
–
Around the sensor and the magnetic tape there may be no additional magnetic fields
(permanent magnets, electromagnets, electrical wires, etc.). How much the readings
are disturbed by interferences depends on the field strength.
–
Electric motors have to be sufficiently shielded.
Tip
Interferences from the vehicle occur permanently, interferences along the track temporarily.
Permanent interferences can sometimes be compensated with offsets (see 6.4.2 on page
26). Constant magnetic interferences (e. g. brakes that are released electromagnetically)
can, starting with firmware version 0.45, be compensated, see section 4.2 on page 16.
10
0
100
100
356
100
100
Front view
Vehicle body
Roadway
Magnet
tape
Magnet
sensor
Side view
‚metal-free‘
areas around
sensor and magnet
tape without
ferromagnetic
materials
Roadway
Magnet
sensor
Nominal
reading dist.
Nominal
reading distance
optional
distance
Vehicle
body
piece
(example)
