A Shielding Effectiveness Test is a comparative measurement of a signal transmitted at a known frequency and signal strength with, or without, the shield in place. The test comprises the following parts;
- Checking Ambient Signal Levels: This establishes the background electromagnetic environment and enables frequencies with high background signals which could mask test signals to be avoided.
- Setting Reference Measurement Levels: This is when signals are transmitted at a set frequency. Antenna separation, power level, and the actual signal level received is noted. This then becomes the measurement level the shielding effectiveness is compared with.
- Dynamic Range: The difference between the measured ambient signal level and the reference level is called the DYNAMIC RANGE. The dynamic range MUST exceed the potential shielding effectiveness of the enclosure by at least 6 dB.
- Shielding Effectiveness Tests: The reference measurement set up is repeated but with the transmit and receive antennas, and equipment now either side of the shielded enclosure. The difference between the recorded signal and the reference measurement is the SHIELDING EFFECTIVENESS of the enclosure. This process is repeated for the selected frequencies and test positions.
Our highly experienced test engineers are externally assessed at regular intervals and carry out shielding effectiveness testing using calibrated transmitters and receivers to accurately define the signal reduced at specific frequencies. All tests are carried out to predetermined international standards to ensure conformity across the industry, and test equipment is calibrated using independent test houses.
