Snap-On UHR Ultra, Service Manual, Page: 53 / 84

51
Diagnostics
The information in target RTP is the “X” “Y”
and “Z” coordinates of the targets relative to
the axix of rotation (Spindle). As described
in the Theory of Operation chapter all the
targets are identical however each target
is rotated differently to properly identify the
location (LF, RF, LR, RR). All relative data
outlined in red should be consistent with
each other based on the target location.
Because each target is the same however
rotated generates either a positive or nega-
tive number.
The graphic below shows a LF target next
to a RR target. If you were to look at the ID
dots you will see that they are in the same location on both the targets however since the entire (RR) target
assembly has been rotated 180º the system assumes that the taget has been placed on the wheel upside
down. If TID had been done with the target upside down the numbers displayed on this screen above will be
way different than the other targets. This is useful to know so that when a user is performing a TID on a set of
targets and there happens to be a 2nd alignment system next to the unit being calibrated it is possible that the
RR target of a 2nd alignment system could be in the field of view of system 1 when calibrating the LF target.
The camera could possibly think the target is turned upside down, thus generating erroneous values. The
same would happen if you were to rotate the LR target and place it next to the RF.
Left Front target
Right Rear target upside down