Take great care to position the arm correctly so as to ensure accurate data reading.
- Keep the arms in contact with the rim until the machine has acquired the values. The
geometric data are displayed in sequence:
• d
distance value;
• di diameter value;
• Lr width value.
When a geometric value is displayed, the corresponding LED illuminates on the display
panel.
- Check the values measured and then return the arm to the rest position.
- If an incorrect value has been acquired during the measurement phase, move the arms
to the rest position and then repeat the operation.
Measurements can also be taken by moving one measuring arm at a time. In this case,
sensors can be used with no preset order.
Pay maximum attention to the measured data since they are influenced by the stored ones.
After setting geometric dimensions correctly and returning the sensors to the rest posi-
tion, the unbalance values recalculated according to the new dimensions are displayed.
IMPORTANT
Bear in mind that the wheel's nominal diameter (e.g. 14") refers to the planes on which
the tyre bead rests, which are obviously inside the rim. The values measured are with
reference to external planes and, as a result, are
smaller than the nominal values due to the thickness of the rim itself. The correction
value therefore refers to an average thickness of the rim. This means that the data me-
asured on wheels with different thicknesses may vary slightly (2 or 3 tenths of an inch
maximum) from the rated values. This is not a lack of accuracy of the measuring devices,
but reflects reality.
If the automatic measuring arm fails to operate, the geometrical data can be entered
in manual mode by following the procedure indicated in the paragraph "Manual wheel
data entry".
In the event of failure of the automatic measuring system and in the version with internal
manual sensor, the geometrical data can be entered using the keypad:
- Press the
button.
- Measure the width of the rim using the calliper provided (Fig. 11).
- Modify the width value displayed by pressing the keys
number is set. The width can be set in millimetres or the values already set can be
converted from inches to millimetres by pressing the
- Values set previously can be increased or decreased quickly by keeping the keys
pressed.
EM 7240 Operator's manual
Manual wheel data entry
until the desired
button for five seconds.
UK
75