Calibration Business Division

Semi Anechoic Chambers

Every product or device unintentionally generates an electromagnetic field due to switching currents and voltages in its digital circuit. In order to determine whether these emissions don’t exceed legal limits, Semi Anechoic Chambers are employed to test new products and devices before they are launched.

Semi anechoic chambers

Is your company in the process of acquiring a semi anechoic chamber? Comtest designs and builds semi anechoic chambers that are perfectly suited for a large range of commercial, military and automotive testing applications. Our chambers are engineered to order for clients in many different industries. Do not hesitate to contact our experienced consultants for more information using our digital contact forms.

What is a semi anechoic chamber?

EMC chambers come in various forms and sizes. One of the most popular forms is the semi anechoic chamber. It’s popular because of its usability and the way its characteristics simulate real world conditions without allowing outside interference. A semi anechoic chamber (SAC) simulates an Open Area Test Site (OATS) in the sense that it has a reflective ground plane much like you would expect under normal use.

However, unlike an OATS, the semi anechoic chamber is housed within a RF shielded enclosure where the walls are lined with absorbing material. Not having to constantly adjust for background noise means testing in an SAC is therefore much faster than in open sites. This makes semi anechoic chambers perfect for fully compliant emissions and immunity testing of various products and devices.

Perfect for commercial, military and automotive testing

Prior to its launch, a new product or device is required to pass testing with regards to radiated emissions and immunity. Every electronic device generates, either intentionally or unintentionally, an electromagnetic field that can interfere with other devices. In order to limit the risk posed by such interference, legal limits are set for the amount of emissions a product or device may generate. Testing these emissions is done in semi anechoic chambers that shield the necessary experiments from background noise as much as possible by using absorbing material on chamber walls and ceiling.

Which type of EMC  test chamber is best for your needs depends on the specific requirements of your research. In order to comply with regulations and common EMC standards, Comtest supplies 3 distinctive semi anechoic chambers, each having their own defined testing distance:

  • SAC3 – 3 meter test distance
  • SAC5 – 5 meter test distance
  • SAC10 – 10 meter test distance

Key Specifications

  • Full compliance emission as per CISPR 16-1-4 (30MHz to 18GHz)
  • Full compliance immunity as per IEC/EN 61000-4-3 (80MHz to 6GHz)
  • Shielding effectiveness according to EN 50147-1 (>80dB at 10kHz)
Applicable standards / Test methods
  • CISPR 16-1-4
  • IEC/EN 61000-4-3
  • EN 50147-1
  • ANSI C63.4
  • FCC part 15
Typical Performance
  • Normalised Site Attenuation (NSA): +/- 4.0dB
  • Site VSWR: ≤ 6dB
  • Field Uniformity: 75% of 16 points ≤ 6dB at 3mtr distance & 1,5 x 1,5m test window