1
SUPA School of Physics and Astronomy, University of Glasgow, G627QB, UK
2
CERN, 1211 Geneva 23, Switzerland
3
Centre de Physique des Particules de Marseille, 163 Avenue de Luminy, 13288 Marseille, France
4
Department of Physics & Astronomy, University of Oklahoma, Norman, OK 73019, USA
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Department of Physics, Indiana University, Bloomington, IN 47405 7015, USA
6
Deutsches Elektronen-Synchrotron , Notkestraße 85, D-22607 Hamburg, Germany
7
Czech Technical University, Technická 4, 16607, Praha Czech Republic
8
Konstantinov Petersburg Nuclear Physics Institute (PNPI), Orlova Roscha, RU-188300, Russia
9
STFC Rutherford Appelton Laboratory—Harwell Oxford, Didcot, OX11 OQX, UK
10
Department of Physics, Oxford University, Oxford OX1 3RH, UK
11
Department of Physics and Astronomy, University of Cambridge, Cambridge, CB3 0HE, UK
12
Academy of Sciences of the Czech Republic, 11000 Praha, Czech Republic
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Abstract
We describe an ultrasonic instrument for continuous real-time analysis of the fractional mixture of a binary gas system. The instrument is particularly well suited to measurement of leaks of a high molecular weight gas into a system that is nominally composed of a
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We describe an ultrasonic instrument for continuous real-time analysis of the fractional mixture of a binary gas system. The instrument is particularly well suited to measurement of leaks of a high molecular weight gas into a system that is nominally composed of a single gas. Sensitivity < 5 × 10
−5 is demonstrated to leaks of octaflouropropane (C
3F
8) coolant into nitrogen during a long duration (18 month) continuous study. The sensitivity of the described measurement system is shown to depend on the difference in molecular masses of the two gases in the mixture. The impact of temperature and pressure variances on the accuracy of the measurement is analysed. Practical considerations for the implementation and deployment of long term,
in situ ultrasonic leak detection systems are also described. Although development of the described systems was motivated by the requirements of an evaporative fluorocarbon cooling system, the instrument is applicable to the detection of leaks of many other gases and to processes requiring continuous knowledge of particular binary gas mixture fractions.
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