16
Drive Shaft Speed Sensor Calibration
NOTE: If you have mounted the magnetic speed sen sor on
a wheel, skip this step and go on to Fine Tuning Speed/
Distance Calibration Values.
Because of the difference in wheel-to-drive shaft ra tios, it
is difficult to determine a calibration value for installation
on a drive shaft by measuring a wheel. You must start
with an estimated calibration value and then fine-tune the
cal i bra tion.
Any number between 10 and 15 (255 mm to 380 mm) is a
good starting value.
NOTE: For fine-tuning the SPEED CAL value, see following
page.
To determine SPEED CAL, measure the distance
of one complete wheel revolution and divide
by the number of magnets installed.
For the console to calculate the correct speed and
measure distance accurately, the circumference of the
sensor-equipped wheel must be entered. Determine the
circumference of the sensor-mounted wheel to the nearest
tenth of an inch (tenth of a centimeter) with the fol low ing
method:
METHOD
Mark the tire with a piece of chalk and mea sure the distance
traveled on the ground for one com plete rev o lu tion.
See
Illustration.
For improved accuracy, it is recommended
that you perform this function in field conditions, measure
several revolutions, and take the average.
Divide the measured revolution by the number of magnets
installed to get your starting SPEED CAL calibration value.
Once calibration of the system is complete, this number
should be fine-tuned for optimum accuracy.
For fine-tuning the SPEED CAL value, see following page.
Calibration
(cont)
Entering Calibration Values
(cont)
Determining the SPEED CAL
(Skip this section if using radar or GPS speed sensor)
DRIVE
Distance travelled in one rotation
Summary of Contents for Calc-An-Acre II
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