Shielded box SHB-50

Shielded box SHB-50A

Shielded-box-SHB-100

Shielded box SHB-200

Shelter in Aluminium

SHIELDING EFFECTIVENESS TEST SET-UP GUIDE

The remainder of this page will address the shielding effectiveness testing process.
No matter the standard for shielding effectiveness, the general procedure for testing shielding effective compliance follows the same process.
First, two antennas are set up on opposite sides of the sample for the test. One antenna acts as a transmit antenna. It is connected to a signal generator to sweep through the required frequency range. The second antenna is a receive antenna. This antenna measures the received field strength. This information is stored in data form. This data represents the signal attenuation or loss of signal through the barrier.
As verification of results, there is a step prior step to the actual measurement of the sample under test. This step requires a calculation of the dynamic range such that accurate results are being made. Therefore, two measurements must be made. The first with no barrier. This means there is nothing between the transmitting and receiving antenna. The second measurement is with a barrier. This is typically a metallic surface that is the best under materials used in shielding. The resulting signal should be the floor-level noise of the antenna and receiver with an additional safety margin. This is usually 6 dB, to take into account for error. Once these two verification measurements are taken, the dynamic range can be calculated. This is simply the difference between the maximum and minimum signals. The amount of dynamic range must be greater than the amount of desired signal attenuation from the enclosure shielding from the sample. Otherwise, the unit outperforms the test chamber and thus concludes the sample shields better than the chamber, which should never be the case. It is important to always verify data, especially if the outcome appears to support this situation.

Shielding Effectiveness Guide

Accessories: Broad-band Antenna 250-3000MHz, Horn Antennas 1-18GHz, Horn Antennas 18-40GHz. Isotropic field sensors.