Abstract: It is necessary, when high requirements are demanded from balances, that the effect of different disturbance variables such as, e.g., temperature and/or moisture on the measuring system be corrected. To this end, temperature and moisture sensors are used from whose output signal correction values are calculated. The invention suggests that a storage area be provided into which the instantaneous measured results of these sensors are stored in succession, where they remain stored for a set time. This data stemming from different times, evaluated with set weighting factors, could then be used to calculate the corrections. This makes it possible to obtain a good correction of changing disturbances even with a different behavior in time of sensors and measuring system.

Abstract: In an electronic balance for application in potentially explosive areas, the weighing system, the electronic evaluation unit and the digital display unit have an intrinsically safe design with regard to the possibility of explosions. All lead connections are supplied with low voltages and the power unit when present is located outside the electronic balance and connected to the electronic balance via an explosion-safe lead and plug connections with an intrinsically safe design with regard to an explosion. In an alternative the power unit can be encapsulated in a pressure-proof manner, powder-filled, force-ventilated or located outside the potentially combustible gaseous explosive area. It is also contemplated that a battery which is intrinsically safe with regard to explosions can also be used in the housing of the electronic balance instead of a separate power unit.

Abstract: In order to reduce the coupling-in of high-frequency electromagnetic interference into the measuring system of electric balances with scale on top and with a metallic balance scale and a metallic housing, a pin (7) which establishes the connection between the balance scale (2) and the load receiver (5) of the measuring system comprises an insulating layer on its surface which is bridged by a resistor (6) located on the pin (7).

Abstract: It is known in high-resolution electronic weighing scales based on the principle of electromagnetic force compensation that the load-dependent development of heat in a coil and a precision resistor can be compensated by sending an additional alternating current through the coil and the precision resistor which is complementarily regulated in its amplitude. In order to regulate the amplitude of this alternating current, the invention proposes a simplified circuit which comprises a highly temperature-dependent resistor, the resistance value of which is set at a fixed theoretical value.

Abstract: It is known in high-resolution electronic weighing scales based on the principle of electromagnetic force compensation that the load-dependent development of heat in the coil and the precision resistor can be compensated by sending an additional alternating current through the coil and the precision resistor which is complementarily regulated in its amplitude. In order to make possible a precise regulation of the amplitude of the additional alternating current even in the case of a small carrying force of the electromagnetic force compensation and of a correspondingly small direct compensating current, the invention proposes connecting in a voltage divider in parallel to the coil and the precision resistor which has a highly temperature-dependent resistor. In this parallel branch direct and alternating current are higher by a constant proportionality factor than in the main branch formed by coil and precision resistor.

Abstract: Electronic weigher apparatus is disclosed which utilizes a plate situated below the weighing scale and above a load receiver which is part of an electronic weight measuring system. The plate is shaped in such a way that thermal air currents generated by the electronic apparatus are carried through a low air resistance path from the interior to the exterior of the weigher casing while a high resistance airflow path prevents air currents from being carried upward from the electronic apparatus to the weighing scale. A collar encircling the scale prevents external air currents from disturbing it during the loading operation.

Abstract: A scale of the electromagnetic force compensation principle, having a stationary permanent magnet system with an air gap and at least one coil positioned in the air gap, the coil being acted upon via a position sensor and a variable-gain amplifier by a compensation direct current dependent on the load of the scale, wherein the compensation direct current flows through a measuring resistor from both ends of which a signal dependent on the load of the scale is tapped off and fed to an analog/digital converter, and further electric circuits are connected therewith which permit an alternating current to flow, in addition to the compensation direct current, through the coil and the measuring resistor and including a regulating or adjusting device which modifies the amplitude of the additional alternating current in such a manner that the joulean heat generated in the coil and in the measuring resistor by the compensation direct current and by the additional alternating current is at least approximately load-indepe

Abstract: An electromagnetic force-compensating weigher with a load supporting device resiliently supported by resilient joints and movable between stops, wherein electric circuitry is connected to produce a slowly decaying mechanical oscillation upon the load supporting device, to thereby reduce the spring hysteresis of the resilient joints.