DMTA-10026-01EN, Rev. D, January 2015
Basic and Multipoint Calibration
87
Figure 4-17 Inaccurate measurement due to bad probe alignment
4.8.1
Other Factors Affecting Accuracy
Nearby magnetic objects and magnetic fields
The probe should never be used on or near ferromagnetic materials such as
carbon steel benches, shelves, brackets, supports, watches or jewelry, or near
electric motors or similar sources of electromagnetic interference. It should be
kept at least eight inches (20 cm) from computers. All of these objects can
influence the probe’s magnetic field and cause inaccurate measurements. This is
especially important when measuring near the maximum specified thickness for
each target type.
Probe orientation
Because the Magna-Mike 8600 measures thicknesses by monitoring small changes
in a magnetic field, its calibration process includes an automatic compensation for
the effects of the earth’s magnetic field. Most commonly, the probe is held at a
constant orientation, vertically in a stand. However in cases where the probe is
used at a different orientation (such as being held horizontally), or when the
orientation is changing as in scanning the outside of a curved part, the Q-CAL
function must be used to make a correction. This is especially important when
measuring near the maximum specified thickness for each target type. Simply
remove the target and press
[Q-CAL]
while the probe is held at the desired
orientation.
Rough or vertical test surfaces
Surface roughness or grooves can cause target balls to momentarily hang up as
the probe is scanned, increasing the apparent thickness. When measuring vertical
surfaces with the probe in a horizontal orientation, gravity can cause the target
Summary of Contents for Magna-Mike 8600
Page 7: ...DMTA 10026 01EN Rev D January 2015 Table of Contents vii List of Tables 169 Index 171...
Page 8: ...DMTA 10026 01EN Rev D January 2015 Table of Contents viii...
Page 10: ...DMTA 10026 01EN Rev D January 2015 List of Abbreviations x...
Page 28: ...DMTA 10026 01EN Rev D January 2015 Introduction 18...
Page 70: ...DMTA 10026 01EN Rev D January 2015 Chapter 3 60...
Page 112: ...DMTA 10026 01EN Rev D January 2015 Chapter 5 102...
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Page 168: ...DMTA 10026 01EN Rev D January 2015 Appendix A 158...
Page 178: ...DMTA 10026 01EN Rev D January 2015 List of Figures 168...
Page 180: ...DMTA 10026 01EN Rev D January 2015 List of Tables 170 Table 31 Calibration kits 163...
Page 186: ...DMTA 10026 01EN Rev D January 2015 Index 176 WINXL about 137...
