Abstract: An apparatus and method for determining at least one process variable of a medium in a container or in a pipeline. The apparatus including: at least a first element and a second element, which are necessary components of the apparatus for determining the process variable and which contact at a contact location, which is exposed to a process temperature. The first element comprises a first material, and the second element comprises a second material. The first material and the second material are selected and matched to one another in such a manner that at the contact location between the first material and the second material a thermovoltage dependent on the difference between the process temperature and a reference temperature arises; and a temperature determining unit measures the thermovoltage and determines the process temperature therefrom.

Abstract: A level transducer has a power supply module, a tuning fork module, a sensing-phase corrector and a controller. The tuning fork module has a tuning fork, at least one piezoelectric driving element, and at least one piezoelectric sensing element. The at least one piezoelectric driving element and the at least one piezoelectric sensing element are stacked on each other, and are mounted on the tuning fork. The power supply module is electrically connected and outputs a voltage to the at least one piezoelectric driving element to deform the at least one piezoelectric driving element. The at least one piezoelectric sensing element is extruded and outputs a voltage signal. The sensing-phase corrector obtains the voltage signal and outputs a clock signal to feedback control the voltage on the at least one piezoelectric driving element to optimize a deformation frequency of each piezoelectric element.

Abstract: A device for establishing and/or monitoring a predetermined fill level in a container is provided, to indicate the fill level in a container and exhibiting a best possible, optimum fit for an application, which device includes: a mechanical oscillatory structure placed at the height of the predetermined fill level, which structure exhibits a membrane and two mutually separated oscillation bars formed thereon, an electromechanical transducer, which in operation excites the oscillatory structure to oscillate with oscillations, such that the oscillation bars execute oscillations perpendicular to their longitudinal axis, a receiver- and evaluation-unit, which uses the oscillations to establish and/or monitor whether the predetermined fill level has been reached, or not, in which the oscillation bars exhibit a shape in which a mass moment of inertia of a liquid quantity, which the oscillation bars move with them in the immersed state in the liquid, is as large as possible and greater than 0.

Abstract: A water drop detection sensor for detecting water drops W adhering to or present upon a windshield by detecting changes in an amount of reflection light and also for detecting the ambient brightness outside of a car or other vehicle, comprising: a windshield 2; a light emitting means 5 for introducing detection light into the windshield 2; and a light receiving means 6 for detecting reflected detection light. The reflected detection light is reflected by total internal reflection within the windshield 2, and the light emitting means 5 and said light receiving means 6 are provided on the windshield 2.

Abstract: The device comprises at least two oscillation rods that are mounted at a distance from each other on a membrane, the edge of which are connected with a screw insert. A clamping screw is connected with the membrane on the side opposing the oscillation rods in such a rigid manner that the clamping screw and the membrane assume a position to each other in which their symmetry axes coincide. The clamping screw is surrounded by a stack of annular piezoelectric elements, electrode rings as well as insulating rings. This stack forms the excitation and reception transformer of the device. The stack-shaped excitation and reception transformer is clamped and mounted between the membrane and a hexagonal nut. The stack braces itself on a shoulder that encompasses the membrane within a distance by the metal ring that closes the stack. The clamping force is chosen such that the membrane is simultaneously prestressed in a concave manner.

Abstract: The invention relates to apparatus (1) for monitoring the level of a liquid within a vessel (3). The apparatus comprises a surface following sensing head (5) adapted to follow the surface (7) of the liquid. A gauging head (9) is mounted outside the vessel (3) at pre-determined fixed distance from the vessel (3). Rotatably mounted within the gauge head (9) is a reel (11) which has wound upon it a flexible elongate tape (13) having its free end (15) connected to the sensing head (5). The flexible tape (13) passes along a defined path of fixed length from the reel (11) to a reference point above the vessel and includes a plurality of level markers (17) which are equally spaced one from another along the length of the tape (13) each pair of adjacent markers (17) being of pre-determined fixed distance apart. A stepper motor (19) is mounted within the gauging head (9) and coupled to the reel (11) to rotate the reel (11) about its axis in two opposite directions.

Abstract: A probe includes a probe foot which is suspended on a cable or a chain attached to a winding drum mounted in a sealed casing above the furnace and which communicates with the interior of the latter via a vertical sleeve passing through the upper wall of the furnace, an electric motor associated with a reducer for actuating the winding drum, and a device for detecting the unwinding and winding up of the winding drum in order to control the speed and torque of the motor. The motor is a servomotor, the speed and torque of which are controlled automatically as a function of the detection device by comparison of the actual speed of the motor with data of desired values dependent on the position of the probe foot.

Abstract: A system for monitoring a level of material held in a confining means, a device therefor and methods of making the same are provided, the system comprising a rotatable reel, an electrically operated motor operatively interconnected to the reel for causing rotation of the reel in either direction of rotation thereof, a flexible support wound on the reel and having a free end, a probe operatively interconnected to the free end of the support to be carried thereby, a brake operatively interconnected to the reel for holding the reel stationary when the brake is in one condition thereof, and a control unit operatively interconnected to the motor and to the brake for causing the brake and the motor to raise and lower the probe by winding up the support on the reel and unwinding the support from the reel, the motor comprising an electrically operated stepper motor.

Abstract: A method and apparatus are provided for monitoring the surface level of a liquid, such as molten metal, by moving first and second sensing electrodes vertically with respect to the surface level of the liquid, positioning the lower portion of the second electrode vertically displaced upwardly with respect to the lower portion of the first electrode, such that the amount of vertical displacement is directly related to the accuracy of determining the liquid level, generating an electrical signal as a function of each electrode position, then moving the first and second electrode vertically with respect to the surface level of the liquid in response to the electrical signal corresponding to each electrode, and thereafter determining the liquid level when the first electrode is in contact with the liquid and the second electrode is in noncontacting position above the liquid.

Abstract: In liquid measuring apparatus, a cable supporting a sensing plate is attached to a drum that is connected via a magnetic clutch with the drive shaft of a servomotor. The servomotor is supported in a pivot mount which is flexibly rotatively connected to the apparatus housing. In response to liquid level changes, a contactless sensor generates a signal which is compared with a balance of moments reference signal in a comparator to develop a deflection signal which, after conversion into frequency pulses in fast servocontrol circuitry, activate the servomotor in one direction or the other as determined by a polarity switch activated by a directional decoder. Inaccuracies due to parts vibrations are compensated for. Also, measurement disturbances caused by waves at the surface of the liquid are avoided with the aid of slow servocontrol circuitry which, after a delay, activates the servomotor with an adjustable frequency supplied by an oscillator.

Abstract: In an apparatus having a magnetic sensing type metal sensor arranged in spaced relation to a surface of metal under measurement and reciprocable in a predetermined direction, a tracing unit for driving the sensor in accordance with a change in the output of the sensor due to a change of position of the metal in the predetermined direction for causing the sensor to follow the surface position of the metal, and a measuring unit for measuring the surface position of the metal based on a current position of the sensor; a metal surface position measuring apparatus comprising a measuring and storing device for measuring a noise component in the output of the sensor due to factors other than a change of the surface position of the metal and storing the noise component, and correction device for correcting the output of the sensor by the stored noise component and causing the sensor to be moved in accordance with the corrected output.

Abstract: A circuit for a servo-amplifier saves power when the position servo has reached balance. The servo input is a high frequency differential transformer having its armature positioned by mechanical means driven by a servo motor controlled through amplifier circuitry. The power to the amplifier is turned off in the vicinity of the servo null point.

Abstract: A contactless inductance interface pickup, having within an external housing an auxiliary housing installed, and formed as a pot, with at least the bottom thereof being constructed from a non-magnetic material, and a clearance between the external housing and the auxiliary housing wherethrough a cooling agent flows around the pickup. Inside the auxiliary housing, in immediate proximity to the bottom thereof, a magnetic circuit is disposed with at least one measuring winding and at least one energized winding.