Page 6 - Instrumentation and Measurement

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INTRODUCTION

1.1 Historical

Instrumentation has always been an integral part of technology. Development from simple level
indicators, Bourdon tubes, moving iron and moving coil meters, etc. has been rapid. Progress in
electrics and electronics has led to centralised recording and display stations with associated data
processing, computing and control systems. Application to control with the requirement of accurate
measuring (sensors), variable converting (transducers) and remote signal transmission (telemetering)
has involved a close relation between measuring, processing and control systems.

These developments led to much greater unmanned operations of many shipboard activities to the
extent that prolonged operation of sophisticated vessels could not be achieved with current manning
levels without computer-based automation. They have also enabled more sophisticated operations
from entertainment systems, to process plant control, survey processes, electric propulsion and
dynamic positioning.

Systems are generally classified by their field of operation. Process control such as temperature, flow,
level and pressure; kinetic control such as displacement, velocity and acceleration, etc.

1.2 Economy

Automation results in more efficient operation and reduced manpower in every case. There is
increased initial cost due to specialised equipment provision which leads to increased insurance
requirements and some increase in certain running costs, for example, staff training, skilled
maintenance, etc. Overall running costs are reduced because of large cost savings in fuel and
general maintenance, due to efficient operation and close supervision, as well as staff reductions.
The annual savings, taking all factors into account, is well proven for controlled plants and the
factor increases with increasing size of plant and machinery.

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