Sartorius

Eduard Bierich

Gunther Maaz

Eberhard Stadler

Franz-Josef Melcher

Christoph Berg

Klaus Dardat

Erich Knothe

Jurgen Ober

Udo Wedeken

A compact balance with a system carrier including a vertical plate, with a balance scale carrier including a vertical plate, whereby the plane of the system carrier and the plane of the balance scale carrier are parallel to one another, with at least three guide rods which run vertically to the plane of the system carrier and connect the balance scale carrier in the form of a parallel guide to the system carrier and with a balance scale fastened in a hinged fashion to the balance scale carrier that a lever is mounted on the system carrier which lever extends parallel to the plane of the system carrier in the space surrounded by the system carrier and the balance scale carrier and that a coupling element connects the one lever arm of the lever to the balance scale carrier whereas a coil for the electromagnetic compensation of force is fastened to the other lever arm of the lever.

Compact balance

There is disclosed a balance based on the principle of the electromagnetic compensation of force with a cylindrical permanent magnet system, with a magnet cover and with a coil for generating the counteracting force that an emitter and a receiver of the optical position sensor be housed inside the magnet cover. The slit diaphragm of the optical position sensor, which extends from below into the area between emitter and receiver, then forms a compact unit with a carrier, e.g., the end of a translation lever, and with a coil and mutual shifts at temperature changes and temperature gradients occur only to a minimal extent.

Balance based on the principle of the electromagnetic compensation of

The invention discloses an electronic balance with a scale on top, a balance scale, a balance scale carrier, two identical guide rods (7,8) which connect in an articulated manner the balance scale carrier and the balance scale in the form of a parallel guide to a system carrier (1/5) fixed to the housing and with at least one corner-load adjustment lever (22') which is connected to the system carrier via a thin area (24) and which carries a support point in the vicinity of this thin area (24) for the end of a guide rod (7) on the system carrier that the corner-load adjustment lever (22') is bent at right angles between the support point of the guide rod (7) and the thin area (24) to the system carrier (1,5) in such a manner that the moving joint (17) of the guide rod (7) and this thin area (24) are at the same height. As a result, even great forces in the guide rods such as those which occur at an off-center loading of the balance scale do not cause any torque on the corner-load adjustment lever and thus result in a very stable corner-load adjustment.

Electronic balance with scale on top and corner-load adjustment

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.

Electric balance

In a parallel rod guide for electronic balances having a measured value sensor, typically corner load adjustments are made by adjusting the parallelism of the two rods and such adjustments are normally sufficient. However, this can eliminate only linearly load-dependent corner load errors. In order to eliminate corner load errors which are non-linearly dependent on the load, the present invention provides an adjustment assembly which varies the resilience of the fastening points on the system carrier side of at least one rod to horizontal forces. The adjustment assembly may comprise, a screw/nut connection whose position can be varied vertically therewith, varying the effective length of a resilient intermediate part.

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Hann-Munden, Germany

Eduard Bierich