Tempest Filters

All of our Tempest Filters have been tested by an independent accredited test house and undergo extensive in-house testing


To ensure compliance with the international performance standards required to protect key infrastructure installations, our range of Tempest Power Filters are designed to prevent eavesdropping, as well as providing surge protection.

The level of Tempest protection on our filters is in accordance with NATO SDIP-27 Level A (formerly AMSG 720B) and USA NSTISSAM (National Security Telecommunications and Information Systems Security Advisory Memoranda) Level 1. And surge protection in accordance with either MIL-STD 188-125-1 for military projects, or IEC 61000-4-24, severity levels 1 & 2 for commercial applications.

Tempest Filter requirements are different to those required for HEMP Power Filters, with the main requirement  being to prevent eavesdropping of confidential information. This is achieved by a combination of a shield to prevent the direct radiation of signals which may be picked up, and by a Tempest Filter to remove conducted intelligible signals on all electrical cables leaving the shielded area which may be superimposed on the cables and interrogated by unauthorised personnel.

To offer a high level of Tempest performance, our standard filters shielding effectiveness performance is designed with an insertion loss of 100dB from 100kHz to 10GHz, which is considered ideal for this application and will continue to perform at 60dB between 10GHz and 40GHz. Specific performance requirements can be accommodated on request.

Other filters within our product range include RF Filters, Control Line Filters, Signal Line Filters and EMP Power Filters.