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Rogowski coils take their name from W. Rogowski who, in 1912, co-authoured a paper with W. Steinhaus entitled 'Die Messung der Magnetischen Spannung (Messung des Linienintegrals der Magnetischen Fieldstärke). This describes a coil wound on a flexible strip of material and a number of experiments to measure electric currents and other magnetic quantities as well as the ability of such a coil to reject external magnetic fields that do not originate from currents flowing through the coil.

An earlier account of the use of a coil wound on a flexible former is the paper written in 1887 by A. P. Chattock 'On a Magnetic Potentiometer' Which describes the use of a long flexible coil for measuring magnetic potentials (magnetomotive force). Chattock's name is now associated with the Chattock Potentiometer which is used for testing the cores of generators and motors for defects.

Rogowski Coils have been used subsequently by several laboratories for specialised electronic current measurements in a wide range of applications.

In 1977 The Central Electricity Generating Board (CEGB) Scientific Services Department in Harrogate began to explore the use of Rogowski Coils to investigate problems in power station electrical plant. The team responsible for this work consisted of John Exon, David Ellison and David Ward. Problems investigated ranged from the monitoring of rotor currents in slip-ring induction motors, sudden short circuit tests, the investigation of unwanted currents flowing in the support frameworks in large turbogenerators, The latter measurements were part of a much larger investigation into overheating in generator cores. See Applications for many other applications in the Power Industry.

During this time the technical experience with Rogowski coils was licenced to Robinson Instruments who marketed a 'Linear Current Transducer' consisting of an integrator (Type 543) with a Worm Coil (Type 545) or a Solid Coil.

Following the privatisation of the CEGB in 1991, Rocoil Limited was founded to continue the work with Rogowski coils. From a small beginning the Company has expanded and now exports specialised current-measuring equipment to more than 40 countries World-wide. We have developed a wide range of products and techniques to cope with different current measurement situations and can easily modify these for special requirements. Our aim is to promote the use of Rogowski coils. It is appreciated that this technology is new even to experienced electrical engineers. We try to understand specific current-measurement applications and will try to suggest the best solution. We are also aware of the limitations of Rogowski coils and will not recommend a system if we think it does not meet the customer requirements. 

Rocoil Rogowski Coils Limited,
5,Almsford Avenue,
North Yorkshire,

tel: +44 (0) 1423 547946
email: david@rocoil.co.uk

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