Stack ST8100 - Page 57

STACK ST8100 Display System Chapter 6. Troubleshooting
Users Guide 47
No. Symptom Possible Cause Remedy Notes
25 Displayed speed
value too high or
too low by a
constant %-age
amount.
System configured
with wrong number
of targets per wheel
revolution
Reconfigure the
system with correct
values
Typical wheel
circumference
for a vehicle is
1800mm / 70”
System configured
with wrong
circumference.
or 900mm / 35”
for a kart
26 No speed reading
Speed reading
erratic, value
jumps high or low
Faulty sensor
and/or wiring
Check sensor
indicator for correct
operation
Rotate the
wheel by hand
and check that
the sensor
indicator lights
up as each
target passes
the sensor
Incorrect sensor
gap (too far or too
close)
Check that the gap
is approximately
1mm
Sensor and targets
moving apart
Fabricate a more
rigid sensor bracket
27 Speed reading
dies after a short
time
Ambient
temperature too
high
Shield the sensor
from radiated heat
from brakes and
bearings. Insulate
sensor from
conducted heat
with fibre washers.
Duct cooling air
around the sensor
Maximum
temperature for
correct
operation of the
wheel speed
sensor is +80
°C
(175
°F)