Most products intended to be sold into the EU require some sort of immunity testing. The results of those tests have to be interpreted to determine the outcome of the tests. The test specifications provide guidelines, but it is typically not a simple process.
With the very limited time we, as a test lab, spend with each product, it is unreasonable to expect the person performing the test to have adequate knowledge of the product to determine with great accuracy the various performance requirements. Without further guidance, we therefore take a very simplistic view of the specifications and apply the following method:
| ESD | Criteria B |
| Radiated RF | Criteria A |
| EFT/Burst | Criteria B |
| Surge | Criteria B |
| Conducted RF | Criteria A |
| Magnetic Fields | Criteria A |
| Voltage Dips & Interruptions | Criteria B & C |
Performance Criteria A: Nothing happens during the test.
Performance Criteria B: Something happens, but the equipment self-recovers.
Performance Criteria C: Something happens and requires operator intervention
A manufacturer may decide to provide some alternatives to the simplistic approach shown above. As can be referenced in the sample criteria shown below (*taken from EN 50082-1*), there is room for a manufacturer to specify “permissible loss of performance.” We encourage manufacturers to plan and specify the performance they expect during each of the tests. Armed with that information, the test personnel can easily determine the criterion that is being observed and whether or not the manufacturer will desire corrective action. We will then include that information in our test report to substantiate our findings.
Performance Criteria A: The apparatus shall continue to operate as intended. No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer, when the apparatus is used as intended. The performance level may be replaced by a permissible loss of performance. If the minimum performance level or the permissible performance loss is not specified by the manufacturer, then either of these may be derived from the product description and documentation and what the user may reasonably expect from the apparatus if used as intended.
Performance Criteria B: The apparatus shall continue to operate as intended after the test. No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer, when the apparatus is used as intended. The performance level may be replaced by a permissible loss of performance. During the test, degradation of performance is allowed. If the minimum performance level or the permissible performance loss is not specified by the manufacturer, then either of these may be derived from the product description and documentation and what the user may reasonably expect from the apparatus if used as intended.
Performance Criteria C: Temporary loss of function is allowed, provided the function is self recoverable or can be restored by the operation of controls.
Reference:
EN 50082-1
EN 55024
For additional text and guidelines see:
http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32004L0108:EN:NOT
http://europa.eu.int/comm/enterprise/electr_equipment/emc/guides/index.htm
NOTE: Information deemed reliable and accurate at the time of posting; users should refer to the actual applicable sections of the official referenced materials.
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