Raising the electromagnetic compatibility of scientific and testing equipment
Manufacturers should know that there’s now a revised EMC standard for scientific, laboratory and testing equipment. This blog post looks at the background to EMC testing and sets out the main changes in this updated specification.
Electromagnetic compatibility (EMC) is the conceptually simple matter of ensuring that electrical and electronic equipment and systems don’t unintentionally generate electromagnetic energy that interferes with, or even damages, other nearby equipment.
Since all electronic and electrical devices have the potential to emit electromagnetic fields, it follows that EMC and EMC testing are growing in importance as the number of electrical devices in use continues to proliferate.
In response, there’s been a corresponding growth in the number of standards that specify EMC emission and immunity requirements for specific categories of equipment. These cover eleven industry sectors – predominantly telecommunications and electrical and electronic engineering – but also including transport engineering (e.g. EMC for ships with metallic hulls, electric vehicle charging systems, and railway signalling apparatus); metallurgy (e.g. EMC requirements for arc welding and resistance welding equipment); building and civil engineering (e.g. EMC requirements for earth-moving and building construction machinery) and health and safety (e.g. EMC test protocols for implantable cardiac pacemakers; and recommendations for the management of unintentional electromagnetic interference with medical devices).
The latest document in this considerable list is BS EN 61326-1:2020 Electrical equipment for measurement, control and laboratory use. EMC requirements. General requirements – a revised standard that specifies immunity and emissions requirements for electrical equipment operating from a supply or battery of less than 1 000 V AC or 1 500 V DC or from the circuit being measured.
What the standard covers
BS EN 61326-1:2020 covers electrical measurement and test equipment that, by electrical means, measures, indicates or records one or more electrical or non-electrical quantities, and also non-measuring equipment such as signal generators, measurement standards, power supplies and transducers.
In addition, it covers electrical control equipment. This is equipment that controls one or more output quantities to specific values, with each value determined by manual settings, by local or remote programming, or by one or more input variables. This includes industrial process measurement and control (IPMC) equipment, which consists of devices like process controllers and regulators; programmable controllers; power supply units for equipment and systems (centralized or dedicated); analogue or digital indicators and recorders; process instrumentation; and transducers, positioners, intelligent actuators, etc.
Electrical laboratory equipment is also considered, including In Vitro Diagnostic (IVD) medical equipment. This is equipment used to prepare or analyse materials, or measure, indicate or monitor physical quantities. This equipment might also be used in areas other than laboratories.
The standard also covers the aforementioned types of equipment when it’s equipped with components that have radio functionality, for example for wireless communication.
Equipment within the scope of this document might be operated in different electromagnetic environments. Depending on the electromagnetic environment different emission and immunity test requirements are applicable. The standard considers three types of electromagnetic environments: basic, industrial and controlled.
This standard is a third edition, and it replaces the 2013 version. The relevant working group (IEC/TC 65/SC 65A/WG 4) identified a need to update the standard for several reasons. It needed to follow the principles in IEC Guide 107 on drafting IEC publications that related to EMC; and it needed to take account of changes in the electromagnetic environment that are being reflected in other related standards.
As a consequence, BS EN 61326-1:2020 includes significant technical changes, the most noteworthy of which are that the immunity test levels and performance criteria have been reviewed; requirements for portable test and measurement equipment have been clarified and amended; and the description of the electromagnetic environments has been improved.
This revision also includes guidance for an assessment concerning the risk for achieving EMC (in Annex B). The revised standard is now fit to ensure the EMC safety of scientific, test and measurement equipment for some years to come.
Please note, following the decision from CENELEC BT, the European edition is temporarily decoupled from the EMC Directive (2014/30/EU) and is not offered up for citation in the OJEU.
BS EN IEC 61326-1:2021
Electrical equipment for measurement, control and laboratory use. EMC requirements. General requirements