|Object Name:||Fuel Flow Sensor|
|Year of Manufacture:||Unknown|
|Location:||Archive Object Store|
This was fairly novel in that it used a vibrating metal vane rather than a rotor to measure the rate of fuel flow. The rate of vibration would be modified by the fuel flowing across it in a ratio proportional to the flow of fuel, and the varying vibration frequency was sensed and converted to a signal that could be used in further real time calculations and indications. My recollection is that the item proved to be either unsuitable, unreliable or not viable for full scale production. Perhaps a more traditional solution proved more suitable.
(A recollection from Graham Swindell of BAE Systems)
In the mid 60’s the Aircraft Engine Instruments Division of Elliotts specialised in the control and management of fuel propulsion systems and its many products included Fuel Flow Transmitters.
The Transmitter is a transducer that measures the rate of fuel flowing through it and converts this to an electrical signal to drive a remote meter. It was developed from the well-proven variable orifice type units that the Division had manufactured for a wide range of civil and military aircraft. A similar unit, Type 7801-11000, was designed for direct engine mounting to the Rolls-Royce Spey on the Trident. It had an accuracy of ± 1.0% of actual flow rate over the cruise band. These units have an ‘X’ in the Serial Number which suggests that they were prototypes or experimental designs.
The Fuel flow business was important to Elliotts and it was in 1964 that the new Fuel Flow laboratory was opened at Rochester. It offered a unique service in Europe. It was designed to test fuel flow equipment for the new generation of supersonic aircraft where fuel temperature of 150°C or higher would be encountered, and units would be required to operate at rigid standards of accuracy under extreme conditions of temperature (up to 200°C ambient) and in areas of extreme vibration.
The Laboratory can achieve gravimetric calibration accuracy within an error band of ±0.1% of flow
rate under the following conditions:
1. Flow rates from 50 to 120,000 lb/hr.
2. Fuel temperatures from -55°C to +180°C.
3. Ambient temperatures from -60°C to +200°C.
There is also a Vibrator capable of producing a maximum thrust of 500 pounds with frequencies of up to 3,000 c.p.s. for resonance searches.