|Object Name:||Air Data System Static Capsule Unit Demonstrator|
|Year of Manufacture:||1960|
|Location:||Main Object Store|
Static Capsule Unit
Marconi Collection Ref: 2035
The Differential Pressure Transducer contains two aneroid capsules, or diaphragms, which expands and contracts with the pressure input from the pitot tube. The case around the diaphragm is airtight and is vented to the static port. Some units will have multiple aneroid capsules to multiply the movement. The difference between the pitot pressure and the static pressure is called dynamic pressure. The greater the dynamic pressure, the higher the airspeed. The movement of the diaphragm is mechanically coupled to a non-linear cam assembly with two rows of fifteen adjustable grub screws to set the desired profile. Within the casing is a wire wound resistor which is driven by the cam mechanism such that an electrical output of indicated airspeed is provided corrected by the cam profile for the non-linearity of the diaphragm movement.
This is an item from the original Marconi Collection and is clearly designed as a demonstrator or a prototype since it has a clear cover over the diaphragms.