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BitBox uses hi-tec equipment for Pre-Compliance testing

BitBox’s Electromagnetic Compatibility Chamber

BitBox has added an Electromagnetic Compatibility Chamber to complement its Pre-Compliance service offering.

Electromagnetic Control

It used to happen frequently that one electronic product would interfere with another. One EMC Standards Report (https://www.emcstandards.co.uk/files/emi_stories_1-95.pdf) by consultancy Cherry Clough, details incidents where uncontrolled emissions resulted in unhelpful outcomes. It tells of a bathroom fan that activated a security light which, in turn, activated an alarm clock; helicopters that tribocharge during flight release arcs of electricity on approach to an offshore metal landing platform, causing local computer systems to fail; and travel trays, designed to keep food and drink from sliding around, wiping the data on laptop computers. Sadly, the impact of such interferences can be tragic.

A leakage somewhere in the device causes these emissions. Legislation has defined what is acceptable for electronic goods to emit. Certification formally recognises acceptable limits and what products for sale should adhere to.

BitBox has acquired a shielded EMC (Electromagnetic Compatibility Chamber) to help test products being designed and manufactured in house with a range of EMC techniques. The chamber is steel-clad and enables the testing of equipment while minimising outside interference. For example, your mobile phone will not work once inside the chamber, similarly, a nearby active mobile phone’s radiation cannot skew the results of a test. This gives remarkable insight in to the integrity of a product under development.

Pre-Compliance Testing

BitBox's testing in the ElectroMagnetic Chamber reduces costs and delivers better products

The BitBox compliance team tests electronic devices for mains conducted and radiated emissions. It is possible to also test for conducted immunity.

Devices that are powered by mains electricity are tested for conducted emissions. A Line Impedance Stabilisation Network device is used to create a known impedance and isolate any unwanted noises to allow the spectrum analyser, or EMI (Electromagnetic Interference) receiver, to take accurate readings.

For the second test, high gain antennas pick up noise from the equipment. The sensitivity of these antennas is great. So much so that a bulkhead in the Electromagnetic Compatibility Chamber wall eliminates the possibility of detecting additional frequencies. The spectrum analyser visualises the data.

If an issue is identified, the equipment can be modified to pinpoint the cause, even down to a single component. In these situations, design engineers investigate the possible sources of failure.

Recognised Value to Customer Success

A spectrum analyser visualises the data from EMC testing

Compliance Manager at BitBox Tim Scott said “We understand the value and importance of an overview of EMC when designing a product from as early in the stage as the FSD [Functional Specifications Document].

“A lack of good EMC techniques can make the difference between a product that gets to the client on time and budget and one that is delayed with more problems than anticipated.

“We believe a holistic approach when understanding your product, helps to identify early EMC design considerations that we can readily adapt to.”


The use of the Electromagnetic Compatibility Chamber brings significant benefits to the work undertaken. Products that require compliance to regulations can be tested early in the design and development process. This reduces the cost of redevelopment. When issues do arise, the BitBox way of working ensures that the causes and resolutions are documented to improve future development lead times.

BitBox provides customers with devices that can be trusted, are reliable and are of a quality that testify to the reputation that we have nurtured for over two decades.