Abstract: An electronic surveillance system for detecting unauthorized persons within a building. The system comprising a microwave transmitting/receiving device which transmits a microwave signal into the area under surveillance and receives microwave signals reflected from the area. The microwave signal having frequencies corresponding to the life functions of any living beings present in the area. The transmitting/receiving device comprising a signal conditioning device, a memory device, and a comparator unit. The signal conditioning device adjusts the amplitude and phase of a portion of the outgoing microwave signal and adds it to the incoming microwave signal, eliminating the carrier wave. The resultant actual signal is transmitted to the comparator unit which also receives a signal from the memory device comprising characteristic frequencies representing authorized occupants. If the results of the comparison are above a predetermined threshold, an alarm is generated.

Abstract: The invention relates to an electronic life detection system, in particular for the searching for buried persons and the surveillance of buildings, having a microwave transmitting/receiving device for generating and radiating microwaves into an area to be investigated and for registering the microwave signal reflected from the area under surveillance and modulated with the frequencies corresponding to the life functions of any living beings present in the area, which device has a first signal-conditioning device, and a second signal-conditioning device.

Abstract: Process for marking an article by means of a pattern, which contains geometrically encoded information and can be evaluated with optical means by irradiation with light, there being provided on the surface of the article in a spatial arrangement in relation to an information pattern which can be evaluated by means of irradiation with UV light but is not visible to a human viewer a further information pattern which can be evaluated by means of visible light, the evaluation of the information contained in the two markings being able to be performed exclusively by means of the information pattern which can be evaluated by irradiation with UV light.

Abstract: Basic commodity or collector's object in particular of a high replacement collector's value with an identification label, whereby the identification label is formed in material of the object itself as an optical mark which is not visible if illuminated with a light source with a wavelength range within the sensitivity range of the human eye but is visible to the human eye if illuminated with a light source outside this sensitivity range the label being situated in an area of a housing surface or other area of the which is optically transparent for at least a part of the wavelength range within the sensitivity range of the human eye and for an additional wavelength range which is outside the sensitivity range of the human eye and which is used to read the label, whereby the undamaged nature of the area is at least to a high degree important when evaluating the replacement or collector's value.

Abstract: Method for applying an object with a label using local radiation of the oct in a predetermined area of the object with high energy electromagnetic radiation whereby the radiation is of a wavelength outside the visible but within the optical range of the spectrum of electromagnetic radiation and that at this wavelength the material of the predetermined area of the object has a maximum of spectral absorption and the parameters of the radiation as a result of material based preliminary tests are thus predetermined that due to the interaction of the radiation with the molecule structure in the predetermined area of the object a permanent altering of the optical characteristics is induced which is perceptable when illuminated in the wavelength range of the absorption maximum, but that the area of the object is not mechanically altered and/or that when illuminated with visible light is not perceptably altered.