Normalized Site Attenuation (NSA)

The NSA test evaluates whether a semi-anechoic chamber or open area test site is suitable for a fully compliant testing facility. Our Normalized Site Attenuation (NSA) measurements follow the procedures mentioned in CISPR 16-1-4 and ANSI C63.4.

We conduct NSA tests to confirm the performance of newly installed, existing, and modified or relocated chambers worldwide. Our expertise covers a range of chamber sizes, from small 3-meter compact chambers with limited ceiling height to high-performance, fully compliant 10-meter chambers.

Semi-anechoic chambers and open area test sites are validated across the frequency range of 30 MHz to 1 GHz using broadband antennas. Measurements are taken in horizontal polarization at 1m and 2m heights and in vertical polarization at 1m and 1.5m heights. The volumetric method is employed, with the typical volume (over the turntable) ranging from 1 meter to 4 meters or more. Testing is usually conducted at distances of 3 meters or 10 meters, with the receive antenna typically positioned between 1 and 4 meters above the ground plane.