|Object Name:||Air Pressure Sensor|
|Year of Manufacture:||2000|
Width (mm): 79
Height (mm): 43
Depth (mm): 76
Weight (g): 231
|Location:||Rack RAA10 [Main Store]|
Tel: +44(0)1252 544433
DoM: 04/08/00 13:03
A Roxboro Group Company
Marconi Avionics Ltd
[etched on the unshielded sensor]
[etched on the shielded sensor]
This object contains two Vibrating Cylinder Pressure Sensors, presumably for a pitot-static transducer role. The air connections can be seen surrounded by blue ring sealis.
The Weston pressure sensor is based around a vibrating cylinder, where the natural frequency of cylinder depends upon the applied pressure. This is classed as a ‘vibrating element’ sensor and exhibits exceptional measurement performance by virtue of its operating mechanism.
The advantage of the vibrating cylinder technique lies in the mechanism that converts from pressure to frequency change. When pressure is applied, the stress generated in the wall of the cylinder affects the frequency directly and, although strain is generated in the material, this has only a small effect on the frequency. The consequence of this is that hysteresis and creep of the material have very little effect on the pressure measurement. In addition, no other mechanism is required to read out the measurement (like a strain gauge). The cylinder acts as the complete measurement system and it is only necessary to maintain it in resonance so that the frequency can be measured.
The consequence of the directness of this measurement technique is that high measurement accuracy <0.01% of full scale pressure (FSP) is achieved with very low drift rates <0.01%FSP/year.