|Object Name:||Pitot-Static Unit|
|Part No:||81 D 14-A-1|
|Year of Manufacture:||1968|
P-S Capsule Unit
Type No. 81D14-A-1
Ser. No. 224/68
"Please handle with extreme care
"Vibrator fitted - very fragile"
In September 1957 Elliott Brothers (London), Ltd., showed for the first time their Air Data Computer Mk 1, which constitutes a complete centralized source of aerodynamic data. It is assembled on a unit-construction basis and can be fitted with just the units required for a particular application.
Pitot-static and static pressure are measured in a two-capsule system by an A.C. pick-off whose signal is amplified and used to operate a motor tacho. Potentiometers provide outputs which are used in the electrical computations. Temperature readings are obtained from a resistance probe temperature unit, suitably corrected and computed. All this data is fed to the Air Data Computer. The Mk1 ADC operated from a 115 V, three-phase, 400 c/s power supply and had a consumption and weight, dependent on the particular arrangement, of 160-180 W and about 30 lb. The Mk 2 version weighed only half as much.
A wide choice of outputs was available in either linear or logarithmic form, including height, I.A.S., Mach number, T.A.S., vertical speed, static pressure, pitot-static pressure, ambient temperature, air density and acceleration.
The outputs were available either as voltage or synchro signals or as shaft rotations; and up to four separate signals could be provided simultaneously from each output.