Auto
Monitor
User Manual Version 7.22
Page 56 of 70
6.2 Tachograph Calibration
The tachograph calibration includes the calibration of the wheels and motion sensor, setting up the
vehicle identification information, date and time of the device, odometer of the vehicle, and
maximum authorised speed for the vehicle.
Figure 47: Tachograph calibration window
The coefficient of vehicle (w) indicates the number of pulses required from the motion sensor for
the vehicle to travel a distance of one kilometre. The constant of recording equipment (k) indicates
the number of pulses obtained from the motion sensor for the vehicle to travel a distance of one
kilometre. The tyre circumference (l), given in millimetres mm, is the average circumference of all
wheels of the vehicle under normal conditions. The tyre circumference is the distance travelled by
the wheel in one wheel rotation. The tyre-size is the size of the tyre marked on the side of the tyre.
The authorised speed is the maximum speed permitted for the vehicle. If the vehicle exceeds this
maximum authorised speed, the tachograph will register an over-speeding event. The odometer
field should have the current odometer readings of the vehicle indicated in the vehicle’s
dashboard. The ‘New Date’ field contains the current date that needs to be set in the tachograph.
The date and time indicated in the settings window is according to the local time of the PC.