Founded in 1945 by Gilbert Tomes and Alec Tidmarsh, Centronic, or Centurion Tubes as it was then known, started life in the back bedroom of Gilbert Tomes' house in Kent, England.

Gilbert Tomes had worked in the research laboratory of Baird Television, pioneering the early development of television technology, before working with Alec Tidmarsh at Cinema Television Ltd. where they manufactured and developed photocells. His innovation combined with his hobby of beekeeping led to the invention of a "Queen Bee Detector", which made use of Geiger counter technology adapted from the work of the German scientists Geiger and Müller. The "Queen Bee Detector" enabled monitoring of movement within a hive by detecting the radioactivity from a spot of luminous paint applied to the body of the queen bee.

His work on electron tubes within the television industry and his interest in radiation detection led to the creation of Centurion Tubes for the commercial development and manufacture of cathode ray and Geiger-Müller tubes. He became sole owner of the company in 1949 when it became a limited company, 20th Century Electronics Limited. By concentrating on chosen specialities of radiation detection and optical sensing, the company grew rapidly to become a world leader in its area of expertise, with many cutting edge innovations arising on the way. With over 50 years’ experience in meeting the challenge of change, the company continues to be as much as ever a "hive of activity".

The Forties

From its inception in 1945 the business grew rapidly, largely through its development of Geiger-Müller tubes in association with the newly formed United Kingdom Atomic Energy Authority (UKAEA) at Harwell. This expansion soon necessitated relocation to larger manufacturing premises and by the end of the decade the company had started to export products and know-how around the world.

The Fifties

In 1951 the company made enormous strides with orders for Geiger-Müller tubes showing another dramatic increase and many new types being introduced. This gave the company its next challenge with the number of staff doubling to 48. In 1953 it moved to new, purpose-built, premises near Croydon where it had sufficient space to accommodate its increasing workforce and allow development of the now urgently needed devices for detection of neutrons. In conjunction with the UKAEA, the company produced Europe's first BF3 neutron detectors.

The boron-10 (10B) isotope is of great importance for neutron shielding and detection as it absorbs neutrons. At that time supplies of 10B were extremely scarce and in some of its more exotic forms boron was even more expensive than gold. A 50 foot high tower was built at the factory to accommodate a distillation column for manufacture of boron isotopes and the company became the world’s first commercial producer of boron-10. Twelve larger, 75 foot, distillation columns were subsequently erected on site to meet the rapid growth in demand for stable boron isotopes, which were required for defence applications as well as for a wide variety of industries including plastics, metals and ceramics. This ensured that the company remained the worlds largest supplier of boron isotope products for some time. Work was also undertaken in the separation of other stable isotopes, such as carbon-13 which is used in medical applications.

By 1957 the factory had been significantly extended and a new group was created to work on photoelectric devices and the development of glass photomultiplier tubes. These were used for detecting scintillations in crystals activated by nuclear radiation. Photomultiplier tubes developed by the company in 1958 were, in fact, an integral part of the first UK satellite to be put into orbit.

Shortly afterwards, and at the request of the UKAEA, manufacture of metal ionisation chambers commenced for the measurement of radiation in nuclear reactors. The company therefore became involved at the early stages of the UK nuclear power generation industry, with the UK being the first country in the world to generate electricity commercially using a nuclear reactor. Since then such devices have been supplied to nuclear reactors worldwide.

The Sixties

No sooner had an extension to the factory been completed and occupied, then there were plans to build another and in 1960 further major factory extensions took place to accommodate an additional 100 staff.

The early 1960's saw interest in development of silicon solid state detectors for nuclear applications. The company funded its own research and development and within two years had entered the revolutionary world of the "silicon chip". Although initially developed for the nuclear industry, semiconductor devices followed which would be used as optical sensing elements in applications ranging from particle sizing to laser guided missiles.

Construction of the boron-10 distillation columns in the fifties had required the company to build its own mass spectrometer leak detectors, tuned to detect minute quantities of helium gas, since no suitable commercial models were available. This experience helped greatly in the development by the company in 1968 of quadrapole mass spectrometers for gas analysis. The systems into which these were incorporated were later to receive prestigious design awards.

The company's achievements were recognised in 1968 by the much-coveted Queen's Award to Industry. While the award was "in recognition of outstanding contributions to technology", it referred in particular to the company's work in the field of stable isotopes.

The late sixties saw the construction and opening of another factory building on the same site, which was to house a new machine shop and drawing office, and was required to accommodate a workforce which had now grown to around 350.

The Seventies

The seventies began with a celebration of the Silver Jubilee of 20th Century Electronics and the company was looking to reach even greater heights in the next 25 years. Manufacture of semiconductor based opto-electronic devices was now in progress and some of these were to be incorporated in a satellite to be launched from Australia. The satellite proved to be a considerable success and since then many satellites have been equipped with the company's optical sensors.

Manufacturing activities for the UK and nuclear power industry were continuing and were further strengthened with the supply of reactor control detectors to the latest UK Advanced Gas-cooled Reactors (AGRs). The company was now also manufacturing neutron detectors for nuclear power stations worldwide (most notably the Canadian CANDU reactors) and also for defence applications.

With the end of the 20th century not too far away, there was a call to change the company name. Rather than a change to 21st Century Electronics when appropriate, an earlier change to a simpler company name was proposed. In 1978 the company began trading under the name Centronic, which was derived from the original name of the company, although the official change of name to Centronic Limited did not take place until a few years later.

September 1978 saw the formation of Centronic Optical Systems Limited to capitalise on the increasing demand for light measuring instruments.

The Eighties

Production of silicon photodiodes for laser detection was now well established and in 1980 this technology was applied to military training. The Centronic designed SAWES (Small Arms Weapon Effect Simulator) system used rifles, grenades, mines, etc., which were modified to incorporate a Centronic laser transmitter. The jacket and helmet of the targeted soldiers were fitted with Centronic laser sensors which would trigger an alarm on detection of laser fire. This principle was extended to include the targeting of tanks using rocket launchers.

There had previously been expressions of interest in acquiring Centronic, but in 1982 a small public limited company, First Castle Electronics plc, made a slightly different approach. First Castle wanted to expand, using Centronic as the flagship of its operation. The purchase of Centronic by First Castle was completed in 1982 and saw the end of Gilbert Tomes' business links with the company that he had created.

The eighties saw a further change in the ownership of Centronic when, less than four years later, The Morgan Crucible Company plc was to bid for the First Castle Group of Companies. The takeover was completed in early 1986 with Centronic and all the other First Castle companies becoming part of the Morgan Electronics Division. Under the new ownership a refocusing of Centronic on its core activities was to begin with the less profitable product lines being discontinued.

The Nineties

The early nineties saw a continuation of the refocusing process and Centronic was no longer manufacturing photomultipliers, cathode ray tubes or mass spectrometers. It had also divested itself of the weapons simulation business which now had closer links to the UK Ministry of Defence. In place of these activities Centronic had consolidated its radiation detector operation further through acquisition of the R.A. Stephens dosimetry business and then in 1992 the Philips ZP range of Geiger-Müller tubes. With the introduction of less labour intensive Computer Aided Design (CAD) for drawing work, and with it now being more cost-effective to sub-contract machining operations to companies with computer controlled machining facilities, the building originally constructed for these operations was to house the expanded Geiger-Müller tube business

It was at the beginning of the nineties that Centronic, with the help of its new CAD capability, won a contract to design neutron detection equipment for use in Nuclear Steam Raising Plant for marine propulsion. As a result of the success of this work further contracts were to follow which formed a significant part of the Centronic business in the nineties and continue to do so.

The nineties also saw significant Centronic activity in the civil nuclear power industry. A spares contract was awarded to Centronic to maintain the availability of detectors for the UK AGRs; the UKs first Pressurised Water Reactor (PWR) power station was under construction at Sizewell and was to incorporate Centronic neutron detectors; and CANDU power stations, also incorporating Centronic detectors, were now being built in the Far East.

These and the previous achievements of Centronic were celebrated in September 1995 at the company Golden Jubilee, which was attended by co-founder Gilbert Tomes. The achievements of the company were also publicised in the September edition of the journal of The Institution of Nuclear Engineers, "The Nuclear Engineer", which was devoted to the Centronic Golden Jubilee.

The electro-optic part of the Centronic business was also the centre of much activity in the nineties. In order to meet the demands of the electronics industry for smaller components and increasing cleanliness, and also to allow for the projected growth in this part of Centronic, installation of a new, higher grade, clean room was commissioned. This went into service in 1998 and replaced the now ageing facility which was used at the outset of semiconductor detector manufacture at Centronic in the sixties and seventies.

The end of the nineties saw, however, the end of the isotope manufacturing capability at Centronic. Eagle-Picher Technologies, the worlds leading supplier of boron products, had targeted the Centronic boron isotope manufacturing facilities. After acquiring the production rights earlier in the nineties, the boron separation equipment was finally removed from the Centronic site in 1999. The tower which once housed distillation columns still continues to dominate the local skyline however, and with the expansion of mobile communications networks the tower now serves a much different purpose.

The 2000s

As the world saw the start of the new millennium, Centronic also saw the start of a new era as the company once again became privately owned. With the Morgan Crucible Company plc wishing to refocus on its own core activities, Centronic was now looking for a new owner. This paved the way for a management buyout, which was completed in August 2000.

With a clear agenda for growth, there was considerable activity in extending the company’s capabilities, in terms of in-house design and manufacturing facilities, innovative techniques in processing new materials and improved product offerings.

2003 saw the acquisition of Raditec. The Raditec business was established by AEA Technology in 1985. On acquisition by the Centronic group the business was relocated locally to a new, dedicated facility in Didcot, Oxfordshire with production activities integrated in to the Centronic site in Croydon. With a strong product range backed by a staff of dedicated and innovative engineers and scientists, the Raditec business offers the design and manufacture of cameras and vision systems that are radiation tolerant and operate in harsh and hazardous environments.

Sadly 2008 saw the passing of the Centronic's founder Gilbert Tomes who died peacefully on 18th June aged 94.

Two further acquisitions were made by the company before the end of the decade, a precision wound components business in 2008 and a Global Precision Engineering in 2009. Both of these businesses were fully integrated on to the main UK manufacturing site in Croydon and have flourished as part of the Centronic family of products.

2010 and onwards…

This decade has seen continued growth at Centronic as the company has continued to invest in its engineering and manufacturing capabilities, and work hard on developing close customer relationships worldwide.

This was rewarded in 2013, as Centronic was acknowledged in a report on the fastest growing SMEs’ in the UK, carried out by London Stock Exchange. Centronic was selected as one of the “Top 1000 companies to inspire Britain” which was published in the Daily Telegraph.

In 2015, Centronic is celebrating its’ 70th anniversary. Since its inception in 1945 which started with the invention of the ‘Queen Bee Detector’ in the back bedroom of Gilbert Tomes’ house in Kent, UK, Centronic has seen remarkable growth and become a world leader in radiation detection and sensing solutions.

Today, Centronic maintains its market-leading position as a manufacturer of a comprehensive range of standard, customised & bespoke sensor solutions for photonic & ionising radiation including Gas-Filled detectors, Silicon Photodiodes, Geiger-Müller tubes, Coil Wound components, Vision systems & high precision machining. With its head office based in Croydon, UK, Centronic employs more than 120 people and serves some of the world-leading manufacturers and operators within the Nuclear, Defence, Oil & gas, Aerospace, Research & Medical industries in a wide range of applications including radiation monitors & dosimeters, x-ray imaging systems, aerospace & defence instrumentations, particle accelerators and numerous nuclear power reactors worldwide such as PWR, VVER, BWR, CANDU & AGR.