Gas cylinders are used in many different situations, such as in research, in industry, in healthcare, and even in the home.
Due to demand in such a wide variety of circumstances, there is the inevitable ambition of gas suppliers to improve the
efficiency of their business. To this end, a prototype inventory management has been implemented in order to provide
such improved efficiency whilst also integrating sensors in order to monitor gas cylinders from a safety perspective. The
prototype system is presented in this paper and its operation described in detail. Preliminary results from the prototype
system are also shown and the sensors implemented for demonstration are discussed. Future work to be conducted is
also alluded to.
Whilst many Wireless Sensor Network (WSN) applications remain in the research domain, there is increased effort in
some circles to apply the concept and related technology to industrial purposes. This study experimentally tests how low
power sensor devices perform in simulated industrial scenarios in terms of communication with a particular focus on
metallic environments, where radio frequency devices tend to fare badly. The study covers experimentation in a number
of different physical environments, as well as with varying materials which may be found in typical industrial situations.
The study also considers two popular operating frequencies for comparison: 915MHz and 2.45GHz. The aim of this
study is to gauge the effect that the environment has on a low power sensor device, as this is important when considering
their constrained operating parameters. In doing this it will be possible to ensure that WSN are practical for industrial deployment and potentially suggest ways in which improvements could be made.
The food industry is keen to have new techniques that improve the safety and shelf life of food products without the use
of preservatives. The use of UV light and ozone (O3) gas are becoming increasingly popular as methods to
decontaminate food and thus extending its shelf life. A microwave radiation device that is a novel source of both
germicidal UV and O3 suitable for the food industry has been developed, which offers speed, cost and energy benefits
over existing sources. With this system comes the need to monitor a number of conditions, primarily UV intensity and
ozone gas concentrations. An optical fibre sensor system is being developed to analyse these properties, in order to
control and optimise the outputs of the microwave plasma UV lamp.
In order to meet increasingly stringent emission control laws it is necessary to develop a sensor that can accurately monitor the level of pollutants entering the atmosphere from land transport vehicles. These pollutants are generally a mixture of hot gases and particulates. An optical fibre sensor is particularly well suited to this task. Due to it's small size and weight it is minimally invasive making it suitable for insertion into the vehicle's exhaust system. Optical fibres are immune from poisoning by the analyte gases, although they do require shielding from airborne particulates. As they do not transmit electricity they are also highly safe and furthermore they are immune from electromagnetic interference. To detect the presence of the gases it is proposed to use an optical absorption technique. The majority of gases of industrial and environmental importance have their fundamental absorption line in the mid-infrared region of the electromagnetic spectrum, with weaker overtones in the near infrared. Due to the greater availability of components, optimised for communications, most optical fibre gas sensing has taken place in the near-infrared region of the spectrum. In this paper mid-infrared optical fibre gas sensing techniques are investigated and the results of the investigation are presented. Due to the inhomogeneous state of the gas flow it is necessary to measure temperature especially just upstream of the after-treatment section where this can rise to as high as 650oC with large temporal gradients. Measurements of temperature of hot gases from a full size test engine using an optical fibre probe based on fluorescence decay time measurements are also presented.
This paper introduces a new concept in the detection and monitoring of the electric field intensity in high power microwave cavities. It is proposed that the optical emission intensity of a low-pressure gas plasma discharge can be used to describe the strength of the microwave electric field that is powering the plasma. This paper discusses the principles of microwave generated plasmas and demonstrates theoretically using Monte Carlo simulations the emission intensity profile of various gas discharges at varying powers at 2.45GHz and 10GHz. A potential probe design, which uses an optical fibre to couple the discharge emission to a remote photodetector, is also introduced. It is aimed to demonstrate the potential for a new technology that will enable the convenient management of applied microwave power and its spatial distribution.
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