Abstract:
This thesis is concerned with the
development of a prototype electromagnetic
flowmeter for dielectric
liquids.
A initial
prototype flowmeter is tested in laboratory conditions with a liquid of
low
conductivity, the conclusion of these initial tests being that the stability of the
flowmeter is below that
required for its design applications. This lack of stability is a
problem reported on several occasions in similar projects involving electromagnetic
flowmeters for dielectric
liquids. Therefore the main body of the work is spent
investigating the causes of instability and trying to redress the necessary problems in order
that a viable
working prototype is developed.
Problems of thermal
instability, electrostatic and electromagnetic shielding are
addressed
along with the causes and effects of all the major noise and unwanted signals
experienced in such a system.
A new
prototype is developed incorporating stability driven improvements. This
new
design is rigorously tested and assessed. The stability of the meter is considered with
respect to its flow related output. Several parameters of operational stability are given in
the
examples considered.
A final assessment is then made of the flowmeters baseline performance and a
account of any remaining instability is given with respect to the issue developed throughout
the thesis.
The conclusions indicate that the electromagnetic flowmeter for dielectric fluids
does
produce a linear output based on Faraday's law of induction. They also indicate that
the
instability experienced previously can be broken into its constituent parts and each
contributor accounted for and reduced, working towards the ideal totally stable flowmeter.
