The identification and quantification of total site emissions is becoming an increasingly important issue, and the measurement of fugitive (non-ducted) emissions is a key part of this. Optical techniques provide unique capabilities in locating and quantifying emissions to atmosphere from previously unknown sources. This talk will present a review of the current state of the art in optical remote sensing for pollutant monitoring. In particular it will cover the use of differential absorption lidar (DIAL) as a technique for mapping and quantifying total site emissions, including diffuse and fugitive sources.

NPL have been actively involved in the development of infrared DIAL as a tool for monitoring VOC emissions from industrial sources for many years. The technique has been successfully deployed on a wide range of monitoring campaigns. A number of case studies of the use of DIAL will be presented, highlighting its unique capabilities for mapping concentrations of pollutants in three dimensions. These will include measurement of total emissions flux of greenhouse gasses from petrochemical plants, plume tracking, and the determination of sources of fugitive emissions.

Presenter profile

Rod is technical lead for the Environmental Measurements Group at the National Physical Laboratory. The group’s work in the environmental field covers the development of new monitoring techniques, validation of methods and the provision of monitoring services. A key area of research over the last 20 years has been the development and use of optical techniques for active remote sensing of the atmosphere. Rod has worked on a range of optical measurement techniques, including open-path FTIR, TDL systems and mobile Differential Absorption Lidars. His current activities include the development of next generation compact DIAL systems, promoting the use of DIAL internationally and the development of standardised methods for the use of optical methods in environmental measurements.

Continuous monitoring of the atmosphere within road tunnels is required in order to maintain acceptably low levels of vehicle emitted, harmful pollutants. Monitoring of the visibility and the concentration of carbon monoxide (CO) within a road tunnel has been a requirement for several years. Combined instruments are available from a few specialist instrument manufacturers. These instruments are based on visible light transmissometry for measuring visibility, and non dispersive infra red (NDIR) spectroscopy for measuring CO. As the CO levels continue to reduce, due to ongoing improvements in vehicle emissions, the oxides of nitrogen (NO 2 and NO) have become significant pollutants, hence there is a desire to also monitor their level in road tunnels. Only a few suitable continuous monitoring instruments are available based on differential optical absorption spectroscopy (DOAS) in the UV. Such instruments are expensive and can not be readily integrated into a single atmospheric monitoring instrument along with the existing CO and Visibility monitors.

The presentation will describe the design, development and in-tunnel performance of a cost effective, continuous monitoring instrument that is capable of simultaneously measuring visibility, using visible light transmisiometry as well CO and NO levels, using NDIR spectroscopy. Achieving the desired sensitivity for CO and NO in a practical, low cost, integrated instrument required a detailed understanding of the operation and performance limitations of the NDIR technique. System modelling was used to optimise the design of the critical components in order to realise the best practical performance. Along with the use of advanced digital signal processing techniques the design resulted in a ‘right first time’ instrument that achieved the target CO and NO sensitivity levels of ±2ppm. These instruments are now in operation in several road tunnels around the world and results from one such tunnel will be presented.

Presenter profile

Colin Edge is the senior design and development engineer at Dynoptic Systems.  Since starting at Dynoptic 18 months ago he has developed several optical based environmental and industrial instruments including dust, smoke and gas monitors.  Prior to this he worked for over 20 years at the Caswell Research Centre (now part of Bookham Technology) where he was involved in the development of many and varied advanced optical and optoelectronic products for telecoms, military and industrial applications.

A new method of optical gas sensing is described that allows multiple species and multiple parameters to be detected using a single laser source and single detector. The technique, dubbed multi-mode absorption spectroscopy (MUMAS), uses a comb of longitudinal modes of a short cavity, multi-mode, laser which spans the spectrum of multiple absorption lines of a single (or multiple) species. The MUMAS spectrum allows concentration, temperature and pressure to be derived. Demonstration of the technique for detection of O 2, C 2H 2, is reported and prospects for simultaneous detection of CO and CO 2, H 2O and hydrocarbons are discussed. MUMAS avoids the complexity and expense of multiple sources and detectors or multiplexing and shows potential for a compact, robust and inexpensive sensor for multiple species and parameters.

Presenter profile

Paul Ewart is Professor of Physics in the University of Oxford. His research involves theoretical and experimental non-linear optical physics, development of novel laser systems and spectroscopic techniques for applications in combustion diagnostics and gas sensing. He completed his B.Sc. and Ph.D. at Queen’s University Belfast before moving to Imperial College , London where he was an S.R.C. Advanced Fellow. In 1979 he moved to the Physics Department at Oxford University . He was a Royal Academy of Engineering Senior Research Fellow for five years supported by British Gas and has collaborated with several major UK industries including Shell, Jaguar, Rolls Royce and De Beers (UK).

TRW Conekt specializes in the specification, evaluation, design and development of sensors for use in hostile environments, and has over 20 years’ experience with sensing systems for road vehicle, aircraft and industrial use. Optical sensors have been developed for several automotive and aerospace applications where the performance characteristics and environmental compatibility of such sensors are of crucial benefit. This presentation will give an overview of the requirements within the automotive and aerospace sectors for which optical sensors are of potential benefit, and will discuss some specific examples of sensors which have been developed at TRW Conekt: fibre-optic sensors for pressure, temperature and fuel metering applications on aero-engines, and the optical torque sensor which is at the heart of TRW Automotive’s production electric power steering system.

Presenter profile

Robert Pinnock is a Principal Engineer within the Systems, Sensors and Safety group at TRW Conekt in Solihull . He has more than twenty years’ experience in the specification, design and development of sensors and sensor systems for a range of automotive, aerospace and industrial applications. Particular areas of interest include the development of optical and opto-MEMS sensors for use in hostile environments, such as on-engine applications in the automotive and aerospace fields, and sensor requirements for on-vehicle driver assistance systems.

The colour and appearance of materials and objects a critical factor in many consumer purchasing decisions and is also important in many industrial and manufacturing processes. In some applications it is the consistency of colour between different components that is most critical e.g. in the automobile industry it is essential that the doors, bonnet, bumpers and wings are all the same colour. In other cases, colour and appearance are indicators of the condition and quality of the raw materials e.g. in the food industry, where colour is a key indicator of the ripeness of many fruits and vegetables. Some industries, such as fashion and cosmetics, would be inconceivable without the ability to control colour and appearance. In all of these areas, there is a requirement to measure colour and appearance in a manner that is not only reproducible from one location to another and one occasion to another, but that is also closely correlated to the visual effect; in other words, the numbers produced by the measuring system need to relate to visual parameters such as redness/greenness, lightness/darkness, gloss, pattern or texture, and so on.

This presentation will provide an overview of the types of instrumentation currently available for measurements of the colour and appearance of materials and will highlight some advantages and limitations of each. The importance of traceable calibration and an understanding of the factors that can influence the measurement results will also be outlined. Finally, new developments at NPL related to the visual appearance of complex surfaces, such as natural and synthetic woods, will be discussed.

Fibre spectroscopy systems are already produced for a broad variety of process-control applications using transmission, reflection, fluorescence and Raman-spectroscopy, but their spectral range is limited to the 0.2-2.4µm transmittance range of  silica fibres. Developments in infrared (IR) fibre optics has enabled an expanded spectral range of fibre spectroscopy from 0.2-2.4µm to wavelengths as long as 18µm. Longer Mid-IR wavelength range from 2 µm to 6-10µm may be covered by Chalcogenide IR-glass “CIR-fibres”, while Polycrystalline infrared “PIR-fibres” from Silver Halides can cover 4-18mm encompassing the “finger-print” part of spectrum. Here, the most informative bands of specific molecular vibrations are easy to interpret due to fundamental absorptions that produce narrower peaks and better sensitivity, as opposed to the broad overlapping peaks obtained with the combination and overtone signals of Near-IR spectroscopy. 

In the production of fine chemicals and biopharmaceuticals, batch reactions are commonplace. Here, there is a need to understand in real-time and without manual sampling the effect of reaction conditions and when completion has been reached.  Techniques that can be employed non-invasively and in situ are of particular interest as it is possible that manual sampling and off-line analysis may not be fast enough.  Optical techniques such as near infrared spectrometry (NIRS) have often been used for in-line monitoring of reactions.  In contrast, mid infrared spectrometry (MIRS) has been less frequently applied in-line until now. 

For environmental monitoring, medical, chemical production and food & drink applications, Fibre Photonics provides hastelloy immersion probes containing a diamond attenuated total reflectance (ATR) crystal and PIR fibre. Most bio-industry surveys identify biopharmaceuticals as the most rapidly evolving sector within the industry. These new therapeutic and diagnostic agents are intended to fight some of the most distressing human diseases, including cancers, Alzheimer’s, and illnesses such as diabetes and asthma, which are rapidly rising in incidence in western societies. It has been rightly claimed that this class of agent will usher in a “revolution in clinical medicine”. Despite this, the complex production processes for these protein-based drugs are challenging and development cycles correspondingly lengthy.

Biotechnological processes are very complex and often poorly understood. Generally, the knowledge of the underlying fermentation phenomena is incomplete. Thus it is impossible to optimise fermentation processes only on the basis of theoretical assumptions. Experiments have to be performed. Due to the expense and time taken to fully explore bioprocess development to provide understanding for process scale-up, it is necessary to design the biotechnological experiments carefully, and often extensively, with respect to the product and process scale-up and eventual manufacture. However, the economic implications of the lengthy development cycles are severe, and faster delivery of these drugs would have significant benefits to health and to national economic competitiveness in this sector. Real-time in-situ, reagent free MIR spectroscopy from micro-reactors to the production site can now be achieved through fibre optic means.

Rapid identification of microbial pathogens is of increasing importance for the early diagnosis and treatment of hospital acquired infections (HAIs). Detection technology currently employed by health service providers relies on either traditional microbial culture which may take 18-24 hours to achieve a confirmed result or PCR based techniques whch use gene sequencing to identify specific pathogens but are uanble to distinguish between viable and non-viable organisms. Both of these techniques require laboratory facilities and skilled personnel to perform the analysis, it is desirable to have a rapid (<4 hours), simple point of care test that may be employed for either rapid diagnosis of infected patients or pre-admission screening. In this presentation we describe a low cost, disposable fibre optic sensor for the rapid detection of viable microbial pathogens using E. coli and S. albus as model systems.

Presenter profile

Lynsey graduated in 2008 from Liverpool University with a 2:1 BSc (Hons) degree in Applied Biochemistry. During her degree she spent one year as an Industrial placement student with EvanesCo Ltd, undertaking research and development of novel optical fibre biosensor devices. Her work included the development of sensors for rapid point-of-care analysis of pathogenic micro-organisms, such as Methicillin Resistant Staphylococcus aureus (MRSA). Early results from this work were presented at the Institute of Physics “Sensors and Their Applications XIV” conference where she was awarded the Instrument Science and Technology Committee poster award. Lynsey is currently studying for a PhD at EvanesCo & Liverpool University , after being awarded an Industrial fellowship from the Royal Commission for the Exhibition of 1851.

The eye, often called the window to the soul, is actually a very effective window into the physical condition of the body. It allows optical measurements of many physiological parameters to be performed painlessly by simply shining a low power beam of light into the eye and analysing the light reflected back. Lein has developed a novel platform optical technology that is being used to exploit the eye to provide health care benefits in areas such as diabetes, optometry and drug delivery.

Presenter profile

Richard Holley works in a small team of engineers at Lein Applied Diagnostics where he is involved in many aspects of their technology including optical design, data collection/analysis, product development and experimental design. He has a degree in Physics and a Masters in Optics and has previously worked in various fields such as 3D displays, microfluidics, interferometry, biochemistry and the film industry.

Overview of OCT & Diffuse Optical Tomography : Optical coherence tomography (OCT) is non-invasive optical method for capturing high-resolution, in situ images of tissue for both research and clinical applications. Diffuse optical tomography (DOT) is a non-invasive imaging technique in which near-infrared light is used to probe the interior of the body for oxygenation and other physiological changes. OCT is mainly used in diagnostic medicine for non-invasive retinal imaging and DOT applications include brain monitoring, optical mammography, and diagnostic imaging of joints and limbs. A major challenge in optical imaging of biological tissue is the strong scattering of visible and infrared light by tissue.

Sensors for DOT & OCT Most OCT applications operate at 830 nm (for retinal imaging) or 1300 nm (for other tissue). In detection, the most important factors are dynamic range, readout speed, and readout noise.

Presenter Profiles

Jennifer Morton is a relatively new member of the Hamamatsu team, having joined just over 18 months ago. She comes from a Life Science laboratory background and is responsible for camera sales to the Life Science market in the UK . In addition to camera sales, she is also responsible for sales of Hamamatsu 's Functional Drug Screening System (FDSS) into the pharmaceutical market. Jennifer has a BSc in Medical Microbiology and has published work on digital image analysis in peer reviewed journals.

Simon Whitbread has been a member of the team at Hamamatsu for just over 4 years, initially joining to take the role of Internal Sales Engineer covering all of Hamamastu's Products. He now specialises in Opto-Semiconductors and is in charge of Hamamatsu 's sales of X-ray orientated products for the whole of the UK . His time as an Internal Sales Engineer developed a broad knowledge of all of Hamamatsu 's products and he continues to be involved in numerous projects covering various applications. Simon has a BSc in Physics and a MSc in Data Communications.