Kaman KD-5100 - Manual (Page 15)

15
15N 20N
Figure 9 Sensor Coil Dimensions
7.5d. If the face of the sensor and the target surface are not parallel (if the sensor
centerline is not perpendicular to the target) more than 2
o to 3 o , it will introduce error to
the measurement.
8. CROSS-AXIS SENSITIVITY
8-1. Assuming you have stable and repeatable fixturing, and have followed all of the rules for
target mounting, pivot points, etc., under certain conditions the system may exhibit signs of error
we classify as cross-axis sensitivity.
8-2. Cross-axis sensitivity may occur under the following conditions:
8-2a. The target must be one with x and y axes of tilt moving about a central pivot point
(see Figure 4). When the target tilts full range in its x axis, it should be able to tilt full
range in its y axis without any change in the indicated output of the x axis (or vice versa).
This may not be the case. Cross-axis tilt can increase the coupling between the sensor
and target, which causes a slight change in output, though there is no change in the actual
distance between the sensor and target. This is a definition of error.
8-2b. This error manifests itself as increased non-linearity of the output at the extreme
end points of target travel only. (This non-linearity can change overall linearity from the
specified 0.1% to about 0.3%.)
8-3. Additional points of emphasis about cross-axis sensitivity:
8-3a. Again, the error manifests itself only at the end points of target travel (the last
20%) when the target tilts fully in both x and y axes.