Sigma Laboratory Tec. (referred to as SLT hereafter) was originally founded in 1965 as an independent electrical testing and research organization in the United Kingdom. In its early development stage, the laboratory primarily focused on testing and evaluation of high-voltage and low-voltage electrical apparatus for industrial applications.

In 1982, SLT was recognized within the UK industrial technical framework as a key electrical testing institution for high and low voltage apparatus, supporting industrial development and technical evaluation activities in the electrical engineering sector.

In 2000, SLT underwent organizational restructuring and transitioned from a publicly supported technical institution into an independent enterprise operating under market-oriented third-party testing principles.

After more than fifty years of development, SLT has become a comprehensive independent third-party testing and research organization in the United Kingdom, providing one-stop services for testing and evaluation of high-voltage and low-voltage electrical apparatus. It is recognized as a laboratory with strong technical capability and advanced testing infrastructure within its field.

SLT is primarily engaged in testing, applied research, technical training, standards information services, and development of testing systems and equipment. Its service scope covers power generation systems, transmission and distribution equipment, high-voltage electrical apparatus, high-voltage switchgear assemblies, low-voltage electrical apparatus and assemblies, industrial electrical systems, marine electrical equipment, nuclear-related electrical systems, automotive electrical and electronic systems, wind power generation equipment, solar photovoltaic systems, energy efficiency technologies, RoHS compliance testing, EMC testing, and seismic performance evaluation.

SLT operates under accreditation from the United Kingdom Accreditation Service (UKAS) and participates in internationally recognized conformity assessment frameworks. It is an IECEE CB Testing Laboratory and is involved in IECEx-related testing activities through authorized international cooperation channels.

The laboratory has established advanced computerized data acquisition systems, integrated laboratory management systems, and real-time monitoring systems. It operates more than 45 specialized testing laboratories covering electrical performance, safety, reliability, environmental adaptability, and system-level verification.

In recent decades, SLT has participated in a series of applied research and engineering projects in collaboration with industry and academic partners, significantly enhancing its testing capability, technical depth, and service scope. The laboratory has contributed to multiple innovation programs and holds several patents related to testing technologies and equipment development.

Its testing capabilities include impulse current testing, short-time withstand current and peak current testing, DC testing, transformer impulse and short-circuit testing, environmental and climate testing, EMC testing, seismic testing, high-voltage direct testing, and high-voltage synthetic testing. These capabilities place SLT among leading high-voltage testing laboratories in Europe in terms of technical complexity and testing capacity, including advanced transformer short-circuit testing and high-energy arc fault testing systems.

SLT also participates in technical committees and standards development activities through cooperation with international organizations and standardization bodies. It maintains technical engagement with institutions such as the National Physical Laboratory (NPL), and collaborates with international organizations including CESI, KEMA, TÜV, and VDE, as well as leading UK and European universities such as Imperial College London, University of Manchester, and University of Strathclyde.

SLT is committed to improving the quality and safety of electrical products by adhering to the principles of scientific management, impartial testing, and accurate data. It operates under the core values of integrity, compliance, and technical responsibility.

Its mission is to support the development of global electrical engineering and testing technologies, provide reliable independent testing services to international clients, and contribute to the advancement of electrical safety, energy systems, and sustainable power technologies worldwide.