Abstract: Weighing apparatus of the load compensation type includes a source of constant current pulses the duration of which is determined by a regulating signal in response to the position of the load receiver relative to the frame, thereby to maintain the load receiver in an initial or zero position during the application thereto of a load to be measured. The regulating circuit includes a PID regulating amplifier that produces a differential signal (D) and a proportional and integral signal (PI). The PI signal controls the operation of a switch that determines the duration of the constant current pulses, and the D signal modulates the amplitude of the constant current from which the pulses are formed. In this manner of using the differential regulating signal component (D), the influence of various deleterious effects on the weighing apparatus, such as vibration, is avoided.

Abstract: A weighing system including a weighing cell (1) which supplies a measurement signal (I) to an A/D converter (3) via a signal line (2). An interference signal (i), superposed on the measurement signal, is decoupled out of signal line (2) at the signal output of the weighing cell (1), rotated by means of an inverter (4) in terms of phase by 180.degree., and again coupled into the signal line (2) at the signal input of the A/D converter. An ohmic resistance (RO) is connected in series in the signal line (2) between the uncoupling node (AK) and the in-coupling node (EK). The interference signal (i) is decoupled preferably capacitively via a series circuit that forms the frequency-determining member of the active low-pass filter including a condenser (C) and an ohmic resistance (R1). On the other hand, a galvanic coupling (R3) is provided for the recoupling of the interference signal (-i).

Abstract: The apparatus which preferably is designed as a scale or balance comprises a circuit which can execute certain function sequences in succession independent of one another by means of function selecting keys. The circuit comprises a matrix which stores a sequence of functions determined by previously run operations and automatically suggests the sequence to the operator by activating or displaying at least one function key corresponding to this determined sequence. A control key is provided, furthermore, in order to interrupt the automatically suggested sequence at any time and to allow the selection of an arbitrary function from the complete scope of functions.

Abstract: The invention relates to a circuit and a method adapted for measuring and digitizing the value of a resistance. The circuit includes and A/D converter operating in accordance with a charge balancing principle, and a resistance network connected to the A/D converter so that the resistance is both a component of the A/D converter and of the resistance network. The A/D converter and the resistance network are interconnected in such a manner so as to permit only a purely resistive measurement. A processor is connected to the A/D converter for obtaining a composite measured resistance value from a plurality of individual measured resistance values. The method according to the invention permits accurate (or precise) resistance measurements having a high degree of resolution of an order of magnitude of 10.sup.5 points. The method is applicable in particular for temperature measurements, for examples in calorimeters or in precision scales, but also in other resistance measurements.

Abstract: The method of measuring positions is based on tracking an interference pattern which is generated when line grids is different line densities are superimposed. According to the present method the line grid of an optical scale is projected onto a line grid formed by a plurality of adjacently arranged diodes, whereby digital switching elements are allocated to the photodiodes and are integrated with same on a common substrate and which compare pair-wise the intensities of adjacent diodes. An absolute measuring of positions proceeds by an additional coding of the line grid of the scale. The method has use in linear as well as curvilinear (angular) measuring of positions.

Abstract: An electronic scale controlling a material feed generates a control signal as the material fed approaches a desired weight. An acoustic tone signal varying in accordance with the control signal and reaching a limiting value when the control signal signifies a zero difference between actual weight and desired weight lets an operator know that desired weight has been achieved.

Abstract: To start a metering process, the operator enters the desired weight value into a display control. The display contains a container shaped figure which is "filled" as material is added to the balance. The rate at which the container fills relative to the rate at which the substance is being applied to the instrument changes during the metering process. It is slow during the coarse starting phase and more rapid during the final fine metering phase. The shape of the bottle preferably corresponds to the "fill" rate, i.e. it is relatively wide at the bottom and has a narrow neck at the top. The display is controlled by a microcomputer.

Abstract: An electromechanical weighing apparatus is disclosed including a device for correcting the load measurement in accordance with the given gravitational force existing at the geographical place of installation of the weighing apparatus. An adjusting mechanism (6) is used to set various switching states corresponding with given different predetermined gravitational acceleration values, respectively, and a calculator or microprocessor (41)--operable in accordance with the aforementioned switching positions to supply from a storage unit corresponding retrievable gravity values--determines the adjusted gravitational acceleration value that is to be used to modify the measured weight signal to produce a geographically-corrected signal of the mass of the object being weighed that is displayed on the indicating device.

Abstract: Slots are provided in at least one wall or surface common to the weighing chamber and the chamber housing the weighing mechanism. These slots are located so that air currents streaming through them will not affect the weighing dish and thereby the measured results. The slots are preferably located in the bottom near the front wall or the rear wall of the weighing chamber. The air currents can then effect rapid temperature and pressure compensation.

Abstract: A weighing system of the electromagnetic load compensation type is disclosed including a counter for counting the weight-responsive pulses which are produced during the periods that the compensating current is supplied to the movable coil to return the movable scale member toward its initial no-load position, characterized by the provision of a temperature-responsive device for supplying to the counter a train of temperature-correction pulses that are used to modify the count of the weight-responsive pulses, whereby a more accurate indication of the applied load is obtained. Thus, an analog signal from the temperature sensor is compared with a sawtooth signal to produce a digitalized temperature-responsive signal which modifies the digital weight signal supplied to the microprocessor circuit.

Abstract: A weighing apparatus is disclosed including a vertically movable load receiving member, and a scale pan carrier resiliently connected with the load receiving member for limited movement with respect thereto, thereby to protect the weighing system against damage upon the occurrence of lateral impact during handling. In the preferred embodiment, a horizontal scale pan carrier arm is connected at one end with the load receiving member for limited movement (a) horizontally axially in a direction normal to the vertical axis of the load receiving member, (b) pivotally upwardly about a horizontal pivot axis, and (c) rotationally in a horizontal plane about the vertical axis of the load receiving member.

Abstract: The plurality of selector buttons or keys previously required for selecting a mode or parameter in an electrical scale is replaced by a single key. Depression of the key causes each of the available modes and/or parameters to be selected in sequence. The title of the then-present mode or parameter is displayed. When the desired mode or parameter has been reached the operator releases the key. Submodes or ranges within a given parameter are set by short depression of the key. The sequencing is controlled by a microcomputer. Jumpers may be provided so that certain modes or parameters are eliminated from the sequence for a given application.

Abstract: The key provided for manual operations of the functioning of an electrical scale is constituted by an elongated bar which rests on two control switches. The control switches are connected to the control circuit of the scale so that activation of either one will result in the furnishing of the same control signal to the control circuit. The location of force applied to the activating member is immaterial, since no matter where the bar is touched, one or both of the switches will be depressed. This permits the operator to control the functioning of the scale without moving his eyes from the display.

Abstract: In a scale wherein the signal signifying the weight is generated by counting of clock pulses over a weight-dependent part of a predetermined time interval, a second counter counts clock pulses in the remaining part of the predetermined time interval. These are added to the clock pulses counted during the weight-dependent part of the predetermined time interval and compared to a reference number which represents the total number of clock pulses in the predetermined time interval. An error signal is furnished if the two numbers do not correspond.

Abstract: Weighing apparatus of the electromagnetic load compensation type is disclosed, including a load support connected for movement relative to a frame, a mechanical-transmission ratio-establishing lever connecting the load support with a compensation coil arranged for displacement relative to a permanent magnet arrangement connected with the frame, a position-responsive circuit for supplying compensation current to the coil for creating an electromagnetic force that reacts with the permanent magnet field to maintain the load support in its initial no-load condition, and indicating means for displaying the magnitude of the applied load as a function of the compensation current. To permit the use of the lever in different lever-ratio-establishing environments without the use of attendant balancing weights, the compensation coil is tapped to define a pair of coil portions (28a, 28b) that are alternately energized by a switching device (42) to apply different forces upon the load support.

Abstract: Conventional electrical scales having independent weighing channels for a reference weight and the actual load with subsequent division of the resulting load signal by the reference signal to furnish the final output cannot furnish a final output signal independent of accelerating disturbances in a large critical frequency region, since changes in load change the dynamic behavior of the load channel. To substantially decrease variations in the final output signal due to such accelerating disturbances, the load signal is additionally coupled to the reference channel by means of at least one frequency-dependent network.

Abstract: The multi-segment indicator can be selectively switched to operate as a range display. For this purpose, the vertical segments are deactivated. Each digit in the multi-segment indicator has a top, bottom and middle horizontal segment. If the measured value is, respectively, less than equal to or greater than a desired value, all bottom, middle, and top segments, respectively are activated. Alternatively, all middle segments are activated if the measured value is within a desired range, the top and bottom segments being activated if the measured value is, respectively, greater than the upper limit of the range or less than the lower limit of the range. The sign of the measured, desired, and limiting values is considered before activation of the corresponding horizontal segments.

Abstract: A weighing system is disclosed of the electromagnetic compensation return-to-neutral type including first and second series-connected compensation coils connected with the weighing pan support, a supply of compensating current connected with the compensation coils, a periodically operable position-responsive switch connected in parallel across the first compensation coil for dividing the compensating current into a continuous first current portion which generally corresponds with the preloading effect of the load support, and a second portion that is periodically supplied to the first coil for periods of time that are a function of the magnitude of the load applied to the load support, and an indicating device responsive only to the second compensating current portion for indicating the magnitude of the load as a function of the compensating current required to return the load support to its neutral position, characterized by the provision of an impedance component electrically connected in parallel with, and

Abstract: An improved weighing apparatus of the electromagnetic load compensation type is disclosed, characterized by the provision of a horizontal one- or two-arm lever connected at one end with a compensation coil carrier device, a first bearing device connecting said lever for pivotal movement in a vertical plane relative to a pot-type permanent magnet, and a second bearing device connecting the pan carrier member with the lever. Preferably the first and second bearing devices comprise vertical flexible hanger straps that are bendable about parallel horizontal axes. In the one-arm embodiment, the lever is connected at its other end with the permanent magnet by the first bearing device, the pan carrier member being connected by the second bearing device to an intermediate portion of the lever. In the two-arm embodiment, an intermediate portion of the lever is connected with the permanent magnet by the first bearing device, and the other end of the lever is connected with the pan carrier by the second bearing device.

Abstract: A sample preparation device comprising a wet mill having a lower discharge opening for discharging crushed wet material from the mill. A continuous flow centrifuge is arranged at a lower level than the mill. Flow means provide a direct communication between the discharge opening and the centrifuge for the direct transfer of the crushed wet material from the mill into the centrifuge.