A novel optical telemetry system applied to flowmeter networks

Abstract

Recently developed transducers utilise the unique characteristics of Deformed Helix Ferroelectric Liquid Crystal (DHFLC) to linearly and passively transduce small voltage signals into the optical domain. These small optical transducers can be retrofitted to an existing flowmeter network where the true benefits of distributed sensing in the optical domain can be leveraged. Signals from multiple sensors can be multiplexed into a single optical fibre for measurement at a remote location. We demonstrate two methods of signal measurement based on a positive displacement oval gear flowmeter. Utilising a reed switch to produce short pulses, errorless flow rate transduction is possible across all flow rates including very low flows. Using a variable reluctance sensor, completely passive transduction of flow rates can be achieved. The same technique can be applied to any sensing network with an electrical signal output.