Abstract: The curve profile of the front edge of an air-filled wing or sports kite of a type which is guided from the ground is maintained without the use of any bracing system. This curve profile, which is very important in determining the flight characteristic of the wing, is controlled exclusively by adjusting the various lengths of balance lines. Two symmetrical line bundles or connecting balances radiate from end points of at least two steering lines and are fastened to various points on the wing base. If so desired, central balance lines can be connected to the wing base without intermediate fastenings. The fastening points on the wing base are located chiefly at the front portion of the wing base. The lengths of the various balance lines preferably increase from the side edges to the middle. However, the rate at which the balance line length becomes greater can increase, decrease, or remain constant, at least in certain areas.

Abstract: Contactlessly operating detectors which are accommodated in a casing provided with a window and which exploit the pyroelectric effect (FIG. 1) are being increasingly used for radiation and temperature measurement. In particular for applications in the infrared range of the spectrum, the manufacture of a suitable absorption layer causes difficulties in achieving the necessary adhesion properties. The absorption layer must have a high degree of adhesion and bonding brought about by gluing, soldering or welding. For this purpose it is proposed that the layer be very thin and comprise a chemically resistant, electrically conductive compound of metals and their oxides such as tin and tin-oxide or silicon and silicon oxide. In addition, these layers are characterized by a degree of surface roughness which is approximately equal to or higher than the wavelength of the radiation to be absorbed.