Testing & Certification

How we measure shielding performance

Shielding effectiveness is measured by method, not asserted by adjective. Our shielding materials are tested by independent EMC laboratories for attenuation across a frequency sweep, and we report the result as a curve rather than as a single headline figure.

That last point matters more than it sounds. Shielding effectiveness varies by orders of magnitude across the spectrum. A number quoted without the frequency it was measured at tells you nothing at all — which is why you will not find a percentage figure anywhere on this site, and why you should be cautious of sellers who lead with one.

Our testing protocol

• Shielding effectiveness. Attenuation measured in decibels across a defined frequency sweep, on the shielding material and, for bags and pouches, on the finished enclosure with the closure sealed — because a Faraday enclosure performs only as well as its seal, and material data alone does not describe a finished bag.
• Material composition. Verification of conductive content and of coating uniformity across the roll, because shielding performance is only as good as its least conductive area.
• Environmental durability. Performance retested after controlled exposure to heat, humidity and mechanical flexing.
• Laundering durability. For textile products, performance retested after repeated washing. Conductive coatings degrade with wear, and a figure measured on new material does not describe a garment after fifty washes. This is where cheap shielding fabric fails, and it is the test most sellers do not run.
• Closure integrity. For bags and pouches, verification that the sealed closure maintains attenuation.

On military standards

You will often see consumer shielding products advertised as meeting or exceeding military standards such as MIL-STD-188-125. We do not make that claim, and we would suggest treating it with caution wherever you see it.

MIL-STD-188-125 specifies high-altitude electromagnetic pulse protection for hardened, ground-based command and communications facilities. It is a system-level installation standard for buildings. A pouch, a bag or a garment cannot meaningfully comply with it or exceed it, and a seller who says otherwise is either mistaken or hoping you will not check.

What we can tell you instead is the measured attenuation of our materials, the frequency range it was measured over, and the laboratory that produced the data.

Engineered to a specification

Our products are built to a defined attenuation specification, tested by an independent laboratory, and supplied with documentation on request. If a product does not perform as its documentation states, we will replace it or refund it in full, including shipping both ways.

That is what we mean by tested. Not a claim — a number you can check.

Request test documentation

Tell us the product and we will send the shielding effectiveness report, the frequency range tested and the method used. Email info@thefaraday.co.

Bulk, corporate and government buyers requiring documentation for procurement: contact sales@thefaraday.co.