The market for multi-channel ultrasonic instruments is characterised by small volumes
of sales and a high ratio of development costs to sale price. The consequence is that the
investment required to develop an instrument is significant and upgrades and other
changes to instrument specification or configuration are difficult for many
manufacturers to justify. These factors are particularly relevant for long range guided
wave technology, where the technology is still relatively new in the market place and
the instrumentation has different characteristics from other type of ultrasonic systems.
To support the design and manufacture of the Teletest® guided wave system (see Figure
1), Plant Integrity Ltd has supported a study into the use of a fully programmable gate
array (FPGA) based control circuits for the electronics, which allows the component
count to be decreased and also permits the control functions to be modified via
software. This has benefits of reduction of size, weight and power consumption of the
electronics and provides a means of upgrading the product without expensive re-design
of hardware