With the speed sensor as an addition to UniLog 1 and 2, it is possible to measure and record flight speeds from 0 to 450km / h. The speed measurement is carried out by measuring the dynamic pressure (i.e. the air pressure generated by the airspeed) and the ambient air pressure.

For the UniLog 2 there is also a special version for speed fliers with a measuring range of up to 600/1000 km / h. This only differs in the measuring range of the pressure transducer used.

The sensors can be switched from 250 to 450 km / h or from 600 to 1000 km / h by a solder bridge in the measuring range. By choosing the lower value you can improve the resolution in the lower area. Since the dynamic pressure increases with the square of the speed, it is difficult to measure very low speeds with this type of sensor. The sensible area of ​​application therefore begins at around 30km / h. Underneath, of course, measurements are also taken, but the error and noise are correspondingly larger.


The speed sensor consists of two parts:

• The pressure tube is designed as a Prandtl tube. The ambient pressure is measured directly on the pressure tube via the ring-shaped holes. In this way, the system is independent of the pressure conditions in the fuselage (eg inflowing cooling air).
• Precision differential pressure sensor with connection to the UniLog. The power supply comes from the UniLog.

The connection between the pressure tube and the sensor is made using two thin silicone hoses.

Technical data:

• Dimensions electronics: 17 x 15 x 15mm plus hose connections 
• Weight electronics: approx. 6g
• Dimensions Pitot (Prandtl) tube: D 4 x 65mm 
• Weight pilot (Prandtl) tube: approx. 4g