20
Conclusion
Once the test methodology is set, the entire EMC check of the complete
product should take no more than 10-15 seconds. It is recommended to
thoroughly explore one sample of the product and note where the “hot” spots
are and what areas are most prone to cause emission problems. This will
help you to pay more attention to potentially troubled spots.
If you would like to “attach the numbers” to the test data, connect output of
the 3M
™
ScanEM-QC Electromagnetic Near-Field Probe to a multimeter so
that you can observe and record the field strength data. You will need the
BNC-to-banana plug adapter for that—please see page 6 of this User’s Guide
for accessories. An ISO-9000 company can benefit from setting numerical
limits to emission based on known good product.
Other Applications
Measuring Efficiency of Shielding
Measure the field strength before and after the shield is applied to know the
actual effectiveness of shielding. Measuring the field strength on both sides
of the shield also helps to evaluate shielding.
The 3M
™
ScanEM-EQC Probe and a multimeter can be used to check the
quality of applied shielding and gaskets in production. A quality inspector
can be supplied with the maximum allowed DC voltage at critical points.
EMC Pre-Compliance and Troubleshooting
Connect the ScanEM-QC Probe to the input of the spectrum analyzer. Set the
spectrum analyzer to the desired settings (if in doubt, use default settings on
power-up). Press and hold the red Operate button. Pass the tip of the ScanEM
Probe over the area in question. Should the emission level be too high, you
may need to change the attenuation of the spectrum analyzer’s input.
