Abstract: A method for calibrating a WIM (Weigh in Motion) sensor built into a road during travel of a calibrating vehicle measures the dynamic wheel force on the road and on the WIM sensor directly at the measuring wheel, depending on time or location. These wheel force data are transmitted to an evaluating unit. As the calibrating vehicle passes over, WIM signal data are simultaneously measured at the WIM sensor and transmitted to the evaluating unit. The wheel force data are synchronized with the WIM signal data in the evaluating unit. A calibration function is determined by comparing the dynamic wheel force data with the WIM signal data.

Abstract: A method for calibrating a WIM (Weigh in Motion) sensor built into a road during travel of a calibrating vehicle measures the dynamic wheel force on the road and on the WIM sensor directly at the measuring wheel, depending on time or location. These wheel force data are transmitted to an evaluating unit. As the calibrating vehicle passes over, WIM signal data are simultaneously measured at the WIM sensor and transmitted to the evaluating unit. The wheel force data are synchronised with the WIM signal data in the evaluating unit. A calibration function is determined by comparing the dynamic wheel force data with the WIM signal data.

Abstract: An accelerometer element of the bender having geometrical outside dimensions and relations wherein the height and width are alike and half of the length. The accelerometer element is built from ceramic materials and consists of two half blocks with a piezoelectric bender element clamped in-between. The high part tolerances are overcome by two fastener gaps, being filled with a special material for microcomponents. This method allows tolerance differences to be compensated by the fastener gaps and its fastening layer. The half blocks consist of a ceramic material to be ground in strips and processed with electronic components in well known batch production methods. Both sides of the blocs are protected with cover plates. The connector recess is filled with a watertight sealing material. The accelerometer element, whether with or without integrated electronics, is fully hermetic and watertight, with only the signal wires protruding on the outside.

Abstract: The detector arrangement comprises a measuring rail with a number of individual elements each having a sensor mounted on a bottom rail and include rectangular elements as force introduction flanges, whose length in the direction of travel is a multiple of their width in the axial direction of the rail. The measuring rail is part of a measuring arrangement for detecting the tire pressures of vehicles in motion. The arrangement includes also at least one contact rail placed ahead of the measuring rail in the direction of travel, and a data acquisition facility. The vehicle speed is determined with the help of the contact rail. The measured values from the sensors yield a tire contact surface with an isobar pattern. From these two, the data acquisition can determine underinflation, normal pressure and overinflation of the individual wheels besides axle loads and vehicle weights, whereby underinflation and overinflation at least are displayed as faults.

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 concerns a sensor arrangement which is installed in the surface of carriageways or runways and serves to detect the wheel loads of vehicles or aircraft and/or their shear components on the surface during travel. The construction of the flanged tube sensor with piezoelectric crystal plates makes possible modular assembly, in that either piezo-plates sensitive to pressure P only, or to shear S, or to combinations of both are installed, since all piezo-plates have the same dimensions. The force introduction flange makes possible a concentration of the force lines onto the measuring arrangement with a substantial mechanical amplifying effect. The packing of the flanged tube sensor ready to install ensures proper fitting and positioning in the installation groove. Here the two rolling force insulation compounds and the foam insulator of the tubular part are important. The application of the invention lies in traffic management for weight detection.

Abstract: A thin disk force sensor having measuring elements of not more than five layers including force introducing layers welded under preloading to a thin disk housing. The measuring elements, weld and disk housing are planarized. A vapor deposited layer is selectively applied to the force measuring elements to increase the applied force compared to the housing.

Abstract: The invention comprises a force measuring system for the dynamic determination especially of axle loads, speed, vehicle wheelbase and gross weight. The force measuring system is laid permanently in the roadway. It is of modular assembly, consisting of the amplifier (11), sensor (12) and terminal module (13). The individual modules may be coupled tightly by plug-and-socket connections, welding flanges or glued flanges. The sensor module (12) consists of a hollow section (1), in which piezo-elements (4) are fitted under elastic preload. The piezo-elements (4) are accommodated in the hollow section (1) at intervals of typically 5 to 10 cm, and they may be connected all together with only one electrically conductive foil (5) to the signal processing facility (19), or groupwise or even singly. According to this subdivision the road width can be sectioned as desired, in order to obtain a road loading diagram for instance.

Abstract: A multi-component dynamometer for measuring forces and torques includes two force introduction plates and pre-oriented transducer elements without housing arranged between them. Each transucer element comprises typically a rectangular plate and two pre-oriented piezoelectric elements fixed thereon, one of these being sensitive to shear in a direction parallel to one edge of the carrier plate and the other being sensitive to pressure in a direction parallel to the normal of the carrier plate. The pre-oriented transducer elements enable the number of piezoelectric elements and electrical connections to be reduced substantially when assembling measuring platforms, as well as the amount of orientation and testing work. The platforms can be made flatter and more rigid, thereby raising the natural frequency. The electronic measuring and evaluation parts can be integrated partially or wholly into the dynamometer.

Abstract: A piezoresistive force-measuring element comprises at least two force-introduction plates with an electrical conductor subjected to plastic deformation arranged between them. The force-introduction plates transmit the forces acting on them without mechanical shunting onto the conductor between them. The change of electrical resistance caused by the force sustained can be used to measure force, accompanied by plastic as well as elastic deformation of the conductor. The typically annular or rectangular force-introduction plates can be fitted inside a housing which may include a bridge circuit for determining the resistance change as well as other electronics enabling the device to be used as a transmitter. By placing the conductor in grooves or anchoring it in the pores of the adjacent plates, an essentially hydrostatic loading of the conductor is obtained, bringing an enormous extension of the measuring range while the measuring accuracy is enhanced owing to the reduced hysteresis.

Abstract: The invention relates to a force transducer with at least 100 pC/N sensitivity. The piezo elements of this force transducer are connected rigidly to the force introducing elements, and therefore require no mechanical prestressing. A diaphragm may be provided and is then the only force shunt with a maximum proportion of 5%. The main force flow runs in these transducers through the piezo elements themselves, thereby keeping the pseudo-pyro effect, which is frequently brought about by mechanical shunting, within very narrow limits. Because of bottlenecks in the heat guide path to the piezo elements and the symmetrical construction of the supports, heat transients are also prevented from exerting an appreciable effect on the position of the zero point. This provides zero point stability, which allows accurate measurements in the 0 . . . 1 N range, even where the ambient conditions are unfavorable from the point of view of temperature.

Abstract: A transducer insert for installing in sensors for measuring mechanical variables includes a semi-conductor body with a measuring diaphragm part of which has diffused-in strain-sensitive resistance paths or capacitor electrodes and also connecting contacts on one side. The semi-conductor body is connected to a base body of insulating material, preferably by an anodic method, through which electrically conductively coated channels pass. The channels open at a recess in the base body which is bridged by the measuring diaphragm part. The electrically conductive layers of the channels extend along the recess to the vicinity of the connecting contacts of the semi-conductor body and are directly connected thereto in an electrically conductive manner by the so-called corner drop method, e.g. by glueing, soldering or thermo-compression. A central projection can be provided in the recess of the base body which creates a deflection limit for the measuring diaphragm part.

Abstract: A piezoresistive transduction element for incorporation into a pressure transducer includes a plate defining a diaphragm zone and preferably of silicon with piezoresistances diffused into it, an insulating plate of a glass material and a base plate. The plates are preferably connected to each other by anodic connections in a series of steps. The base plate is made of a material having substantially the same coefficient of thermal expansion as that of the material of the plate which defines the diaphragm zone. Furthermore, the dimensions of the base plate are matched to those of the diaphragm plate. By these measures the deformation forces exerted by the base plate and diaphragm plate on the insulating plate upon changes in temperature are of substantially the same magnitude and therefore there is minimum bending of the diaphragm plate. A symmetrical transduction element is created which has minimum zero point displacement and minimum sensitivity changes in use.

Abstract: A piezoelectric crystal element for use in force and pressure transducers and accelerometers, consisting of a monocrystalline cubic-polar material with electrode faces that intersect one of the crystallographic principal axes X,Y,Z at an angle .alpha.'=arc sin .sqroot.p and the other principal axes at .beta.'=.+-.1/2 arc cos p, wherein p=0 for the piezoelectric orthoaxial shear effect, p=1/3 for the longitudinal piezoeffect and p=1 for the transverse piezoeffect.

Abstract: The invention relates to an acceleration pick-up which can be produced at favorable cost in large numbers, for which new constructional means are used. The apparatus consists of a mushroom-shaped support screw (6,56), which is inserted directly in the synthetic material housing (8) of the measuring device and which mounts and retains both the mass sensor arrangement (1, 2, 3, 4), the printed circuit board (15) as well as the housing cover (9). In the immediate vicinity of the mushroom-shaped head (7) at least one flat holding magnet (30) is likewise inserted directly in the synthetic material housing (8). In order to screen the sensor arrangement against disturbance effects, the inside of the synthetic material housing is coated with a conducting metal layer (26,28,66) for inner screening, which is connected to the screening of the connecting cable piezoelectric, piezoresistive, inductive or other systems can be used as sensor elements.

Abstract: A piezoelectric crystal element comprising a member of monocrystalline material of symmetry class 32 has two force introduction surfaces essentially parallel to a crystallographic `a`-axis but inclined with respect to the `c`-axis so as to intersect the latter at a specific angle e.g. 10.degree. to 40.degree. to considerably reduce over a desired temperature range the temperature dependence of transverse of antiaxial shear sensitivity.

Abstract: A piezoelectric transducer element which can be used in force and pressure transducers is made from a quartz element which is prestressed within the transducers. The prestress is applied within a certain orientation with respect to the lattice plane (0 4 4 3). The transducer may include both disc and rod-shaped quartz elements.