Log in to personalise your experience and connect with IOP.

Business and innovation

Hirst Magnetic Instruments

Hirst Magnetic Instruments Ltd is an innovative magnetics technology company, which has taken scientific processes into industrial production areas involving magnetising and the accurate characterisation of magnetic components. Its recent advance in the latter sector promises significant increases in product yield in the manufacture of EV motors, making an important contribution to this green energy sector.

Hirst Magnetic Instruments Ltd is a well-established, research-led magnetics company with a history of developing groundbreaking technical solutions which address strategic technology sectors. 

In its application, magnetics is a complicated area of physics, combining aspects of materials science, chemistry, advanced mathematics, mechanical engineering and electrical technology. 

A diagram of Hirst Magnetic Instruments pulsed field magnetrometry

The company is headed by John Dudding, a veteran of the UK magnetics industry.

Hirst designs and manufactures three product streams: magnet and magnet material characterisation equipment, magnetisers and gaussmeters which are used for accurate magnetic field measurements in laboratory or industrial environments.  

Permanent magnets enable green energy when applied to motors and actuators and have an important and growing role in meditech, transport, aerospace and everyday life. 

This has put pressure on evolving historic scientific laboratory magnetic technologies to industrial production level. This is particularly necessary in electric vehicle supply chains, a key part of which is permanent magnet electric motor production.

Hirst already produces magnetisers for this sector but industrial materials characterisation is also needed to make volume production possible and Hirst has successfully addressed this challenge.

Hirst designs and manufactures state-of-the-art magnet and magnet material characterisation systems to meet customer requirements at the materials and finished industrially shaped magnet level.

These pulsed field magnetrometrys (PFM) operate on an open-loop magnetic circuit and can fully characterise magnetic materials in seconds.

Hirst has now developed a significant advance of the PFM process with mathematical support from the University of Exeter. These new PFM self demagnetisation field function (SDFF) units allow closed-circuit magnetic measurements to be made in open-circuit circumstances, something which has not been possible before. 

This is an essential step needed for the characterisation of actual production magnets prior to assembly and magnetisation. 

This is an industry first and solves a high-value industrial market challenge.

This technology extends the PFM open-loop process, allowing closed-loop measurements to be made by using a proprietary new field interpretation model operating on a proven technology platform.

This enables a high-yield volume permanent magnet motor manufacturing supply chain and quality assurance operations worldwide. 

The SDFF technique can be applied to all 'open' magnet characterisation techniques, in the laboratory or factory, where it can offer potentially 100% yields by ensuring that every magnet in the assembly has the same, specified characteristics required by the application.

Essentially this advance enables a high-yield volume manufacturing of permanent magnet-based products, ahead of other techniques.

Hirst also makes high-power magnetisers for permanent magnet product production lines, where it has 75% of the UK market.

With the growth in electric vehicle motor production and the resulting demand for production line operation, Hirst’s SDFF equipment beside Hirst’s magnetisers should grow with the growth of electric vehicle supply chains, as electric transport replaces internal combustion vehicles.

A Hirst Magnetic Instruments pulsed field magnetrometry machine