Introduction
Whilst many pass/fail standards exist for screening equipment for applications such as aviation security, NPSA identified a need for test methods that evaluate baseline performance of products suited to screening applications in high footfall locations. Such products will typically be designed to discriminate larger threats from benign items (i.e. everyday items carried on a person or in their bags) and will be able to screen large numbers of people and / or their belongings without them needing to slow down significantly or remove contents of pockets etc.
As high footfall locations encompass a wide variety of different venues and events with different detection priorities, different visitor arrival rates, and differences in the possessions visitors bring, a pass/fail approach to testing screening products isn’t appropriate.
Instead, there is a need for test methods that are reproducible, practical and proportionate to conduct. These tests must provide statistically valid results on system performance, including both threat detection and false alarm rate.
In partnership with technology developers, end-user site owners and operators, government stakeholders and independent experts, NPSA has produced a suite of test methods to address this gap. The test methods are technology agnostic and are designed to be conducted by product manufacturers (or their appointed testing contractors) without NPSA’s involvement. They are intended to assist:
- product manufacturers in communicating their systems’ capability to detect various categories of threat, as well as anticipated nuisance alarm rates for various categories of typically carried items (pocket contents, electronic devices, bags, etc).
- site owners and operators (and security service providers) in determining what high footfall screening product(s) (and settings) best meet their requirements.
Due to varying operational requirements and technological differences, three test methods are available:
- Discriminative Metal Detection (DMD) Systems test method (Version 2.0 - April 2026)
- Discriminative Threat Detection (DTD) Systems test method (Version 2.0 – April 2026)
- High Throughput Bag Screening (HTBS) Systems test method (Version 2.0 - April 2026)
NPSA makes the test methods available to bona fide product manufacturers (and their appointed testing contractors) on request. NPSA periodically reviews and updates the test methods in light of learning, feedback received, and evolution of both the threat and available products. When updating test methods, NPSA will make every effort to ensure that test results obtained using previous versions remain valid.
Each test method comprises various classes of threat and benign items, in each case categorised broadly by type and size, with the intention of determining how a product performs. Note that while the threat classes are primarily focused on items that may be used by terrorists to achieve mass or multiple casualties (improvised explosive devices, firearms and ammunition, larger bladed weapons), it is recognised that users may also have other detection priorities, for example, protest materials.
These tests do not include an assessment of other, primarily non-functional, aspects of system performance such as mechanical and electrical safety, operating environmental conditions, power consumption and usability as they can be evaluated using techniques available in existing standards.