High Voltage Instruments Ltd.

World-class reputation for product quality, innovation and value for money. Our products are now used and approved by the major electricity boards in the United Kingdom. Continuously proven fit for purpose in the field worldwide for more than 50 years.

High Voltage Detectors

High Voltage Detectors

Widely used throughout the electricity industry to determine that high voltage lines are de-energised prior to work being carried out thus ensuring safety of personnel.
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Dead Break Testers

Dead Break Testers

Specifically designed for use on capacitive test points of separable connectors and on insulated polymetric cables in fused cable boxes.
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Live Line Indicator

Live Line Indicators

Battery operated electronic unit that has been specifically designed to test DC systems – with particular relevance to Mass Transit Railway (Metro) & Tram based models.
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Wireless Phase Comparator Kit

Wireless Phase Comparators

Designed to determine the Phase Relationship between two energised conductors at the same nominal voltage and frequency, without the need for connecting cables.
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LLT-11kV Live Line Tester Kit

Live Line Testers

Designed to perform measurements for both live voltage testing and phasing on overhead lines, in substations and within switchgear compartments.
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High Voltage Indicator

High Voltage Indicators

Used to indicate the presence of voltage to ensure the safety of maintenance or installation personnel allowing the apparatus to be safely earthed.
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Who We Are

Originally formed as Everett Edgcumbe, High Voltage Instruments Ltd. has been at the forefront of test instrument design since it’s formation in the year 1900. Since then the company name has changed to Edgcumbe Instruments Ltd and the Metrohm brand was created.

The Metrohm brand is held in the highest esteem internationally for product quality, innovation and value for money. Following a management buy-out in April, 2007, the Metrohm range of High Voltage products designed by Edgcumbe Instruments were added to the High Voltage Instruments Ltd portfolio.

Starting from 2007 the company has been operating from Glasgow, Scotland. Following a takeover by T&R Group in November 2020, High Voltage Instruments manufacturing facilities were moved to a more spacious, top of the line manufacturing complex located in Guildford, Surrey, in 2022.

Years Experience
Instruments Sold
Years ISO9001 Certified

T & R Group

Transformers & Rectifiers Ltd.

Transformers & Rectifiers Logo Landscape

British company with a proud 65+ year history for supplying transformer equipment worldwide with a proven global reputation for product quality.

T & R Test Equipment Ltd.

T&R Test Equipment logo

Trusted and reliable worldwide, T&R Test Equipment Ltd. is one of the United Kingdom’s leading manufacturers of heavy current and high voltage electrical test equipment.

High Voltage Instruments Ltd.

High Voltage Instruments

Originally formed as Everett Edgcumbe, High Voltage Instruments Ltd. has been at the forefront of test instrument design since its formation in the year 1900.

Why Us


ISO 9001 accredited for more than 20 years. Our brand has a solid reputation based on the quality and reliability of our products. All our customers benefit from our commitment to delivering the highest possible quality.

History of Excellence

We have been at the forefront of test instrument design since 1900. Since then our products have been used by engineers all around the world. Today we are known worldwide for product quality, innovation and value for money.

Approved Products

Our test instruments are in use worldwide and approved by the major electricity boards in the United Kingdom. As such, they have been continuously proven fit for purpose in the field for more than 50 years.

Global Reach

Our distribution network has been continuously developed for more than 50 years. It includes only authorised distributors and trusted vendors. That enables us to provide our products worldwide.

Get A Quote

Getting in touch with us or requesting a free quotation has never been easier.

Whether you need more information about our products, after-sales support, pricing and lead times, the contact form can be your easy to use gateway to our sales department.

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Highly Qualified Team

Managing Director

Neil McFadden

Managing Director

With over 30 years in the electrical engineering arena and Worldwide Director level postings, Neil has gained a proven record and a wealth of experience in management, sales and operational disciplines.
Commercial & Sales Director

Gary Biggs

Sales Director

Experienced Sales Director with a proven record in the electrical and electronic manufacturing industry. Skilled in Negotiation, Marketing Management, Business Planning, Sales, and International Business.
Production Manager

Nick Eldridge

Production Manager

An expert in the field of high voltage test equipment. His work experience speaks for itself, began in production and became a top seller before taking on a new role as our production manager. As part of his hobbies, he cultivates delicious fruits and vegetables and cooks them for his family.
Quality Manager

Roy Mepham

Quality Manager

Experienced manager of quality, health, safety and environment with over 30 years of experience and multisectoral experience in the establishment, maintenance and improvement of management systems in accordance with ISO 9001, 14001 and 45001 standards.

Get In Touch!

Our Customer Service team is always keen to help. Whether it is by email, phone, or simply visiting us, we will be happy to assist.

Do not hesitate to contact us if you require any kind of support, guidance, pricing or lead times on our products.

Business Hours

Monday – Thursday 08:30 – 17:00

Friday 08:30 – 12:30


+44(0)141 4405800
+44(0)1483 207428