JASIS (Japan Analytical Scientific Instruments Show), one of the largest exhibitions in Asia for analytical and scientific instruments, took place recently at the Makuhari Messe in Chiba, Japan.

Malvern Instruments received some great news at this meeting, which we are delighted to share with you: we won the “Analytical and Scientific Instrument Heritage Certification” award for the High Speed Digital Correlator and Probability Analyser System Type K7023.

Mr Koichi Hioki received the award on behalf of Malvern Instruments.

The aim of this award is to communicate information to the Japanese people about valuable analytical technologies and scientific instruments that contribute to the country’s life, economy, education and culture, and will be important to future generations as part of their scientific and cultural heritage.

Rigorous deliberations were carried out by the selection committee of six experts from industry, government and academia, and 15 technologies were selected. These were viewed by the committee as the equipment and technologies that best communicated the “power of science” to the world.


The Malvern Instruments’ High Speed Digital Correlator and Probability Analyser System Type K7023 was launched in 1971 and referred to as the “Malvern correlator”.

Before the launch of the K7023 correlator, researchers had built their own devices, however it is our understanding that the K7023 was the first commercially available digital correlator.

The K7023 correlator was jointly developed by scientists at the Royal Signals and Radar Establishment (RSRE) which was a research establishment within the UK Ministry of Defence and Precision Devices and Systems (PDS). The development cost was partly funded by the National Research and Development Corporation (NRDC) in the UK. The pioneering research work on photon counting and photon correlation was carried out by a number of scientists at the RSRE in the 1960s including Dr. E. R. Pike, Dr. C. J. Oliver, Dr. E. Jakeman and Mr R. Jones who received the coveted MacRobert award with Mr D. S. Trudgill in 1977 for the development of the Malvern correlator. A patent was granted to the RSRE for their correlator design and the NRDC negotiated a licensing agreement for the technology with  PDS (which later became Malvern Instruments) in February 1971 to allow PDS to manufacture the K7023. Steve Trudgill was the Managing Director of PDS and he named the correlator after one of his daughters (Katherine) and the reference number of the Great Western railway Penrice Castle steam locomotive (7023) of which he was a fan !

A correlator is a signal analysis device which can be used to look at the correlation in a signal with a delayed version of the same signal.

By averaging and multiplication of the signal with a delayed version of itself it is possible to extract periodicities or characteristic decay times present in the signal.

In practice the Malvern correlator was used in combination with a photomultiplier to study the fluctuations in the intensity of scattered light over short time periods from microseconds to milliseconds.

This was referred to as Photon Correlation Spectroscopy (PCS) and could be used to determine the translational diffusion coefficient of colloidal particles or molecules undergoing random Brownian motion in a liquid.

This correlator technology found another early application in laser Doppler velocimetry (LDV), which could be used to measure the flow pattern of air over a wing or around an aeroplane engine or to measure the flow rate of blood in the retina of the human eye.

Today the same technology is used in the Zetasizer Nano instrument to determine the velocity of nanoparticles undergoing electrophoresis in an electric field and to calculate their zeta potential

A well-deserved award, for an instrument which was pivotal in the analysis of particle size and particle size distribution.  Many thanks to JASIS for this acknowledgement of our work.


  • PIKE, E. R.. Lasers, photon statistics, photon-correlation spectroscopy and subsequent applications. Journal of the European Optical Society – Rapid publications, Europe, v. 5, sep. 2010. ISSN 1990-2573. Available at: <>. DOI:234.
  • Major engineering award for Malvern research team
    Radio and Electronic Engineer
    Year: 1978, Volume: 48, Issue: 3
    Pages: 146 – 148, DOI: 10.1049/ree.1978.0021
    IET Journals & Magazines