Abstract: A pressure sensor includes a housing, an interior chamber of which is sealed by a diaphragm, and a flexible measuring element, which is positioned separately. In addition, the pressure sensor includes a transmission element, which is formed as a chip and is used to transmit force from the diaphragm to the measuring element. In response to a selected deformation of the measuring element, a stop element comes into contact with a region of the transmission element and opposes the applied force. Therefore, it forms an overload protection. The stop element may be configured as a bending bar and/or form a second measuring element, the first measuring element being configured to measure relatively low pressures, and the second measuring element or stop element being configured to measure relatively high pressures. The pressure sensor thus provides a plurality of measuring ranges.

Abstract: For a comparative material testing of similar formed parts based on their dynamic behaviour under acoustic excitation vibrations, in order to obtain clear-cut information about the material properties it is necessary to assure constant excitations of the vibration generator and a constant pressing force when coupling this to the object being tested. This is accomplished by using a piezoelectric actuator in an assembly unit with an electromechanical sensor and a coupling element, whereby the excitation voltages of the actuator are monitored and its vibrations passing into the formed part are registered by the sensor.

Abstract: The invention relates to a combined force, strain and sound emission transducer and a coupling method. The sound emission sensor (1) forms an assembly unit and is intended specially for measuring high-frequency sound emissions (up to around 2 MHz). It consists of a piezoelectric measuring element (9), an assembly base (8) with circumferential coupling diaphragm (7), and an encapsulant (10) partly surrounding the measuring element (9) and partially the assembly base. The assembly unit could contain also a resistor (11) paralleling the measuring element (9) and forming a high-pass filter with the capacitance of the sensor (1). The coupling diaphragm (7) lies in a recess (14) of the housing bottom (4), whose bottom surface (5) is at a distance from the measuring object (15) corresponding to the prestressing distance s when the diaphragm (7) is unloaded.

Abstract: The invention comprises a force measuring system and an assembly procedure for the dynamic determination especially of axle loads, speed, as well as for assembly of force and acceleration sensors. The force measuring system can be laid permanently in the roadway. It is of modular assembly, consisting of the amplifier, sensor and terminal module. The sensor module consists of a hollow section, in which piezo-elements are fitted under elastic preload. The hollow section is designed so that it can be opened elastically by lateral clamping, to allow mechanically interconnected piezo-elements to be inserted simply. After releasing this clamping, the piezo-elements are under high elastic preload. The same design principle can also be applied generally to force pressure and acceleration sensors. The elastical clamping force, vital for perfect force transmission to the piezo-elements, is for assembly purposes easily overcome by a proper lateral clamping force.

Abstract: The invention relates to an acoustic emission transducer and a coupling method. The acoustic emission transducer (1) forms an assembly unit and is intended specially for measuring high-frequency acoustic emissions (up to about 2 MHz). It consists of a piezoelectric measuring element (9), an acoustic transmission base (8) with a circumferential coupling diaphragm (7), and an encapsulant (10) which partially encloses the measuring element (9). A mounting screw (3) serves to fix the transducer to a measuring object. The coupling diaphragm (7) lies in a recess (14) of the housing (2), whose bottom surface (5) is at a distance from the measuring object (15) corresponding to the prestressing distance s when the diaphragm (7) is unstressed.