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: A balance having a setting means with which the relative precision of the weighing result is to be determined can be set by the user. The balance then adapts automatically to the set relative precision. This adaptation can occur, e.g., in the number of positions displayed, in the step width in the last particular position, in the selection of the integration time, in the filtering of the measured values in the digital signal processing unit, in the frequency of the taking over of the measured value into the display and/or at the time of the emission of the standstill signal or of the measured value release signal.

Abstract: In an analytical balance with a pan and a four-bar mechanism which keeps the balance pan parallel horizontally during its vertical travel, the one vertical side of which is held fast to the housing, the other vertical side of which, in the form of a coupling piece, carries an extension which receives the pan, and both horizontal sides of which are connected in an articulated manner by an upper and a lower rod to the vertical sides, whereby the four-bar mechanism is loaded by the restoring force of a load converter, the extension (16) which receives the pan (17) is L-shaped, the horizontal L-shank (pan arm) (16") carries the pan (17) rigidly connected to its free end and the vertical L-shank (bearing arm) (16') is mounted on the bar (18'") of a U-shaped arm bearing (18) which projects above and below over the vertically movable end (9) of the four-bar mechanism (5, 6, 7, 8, 9) with its two horizontal U-shanks (18, 18") in the rod planes and is rigidly fastened to it in two vertically superposed bearings (118')

Abstract: In a spring body which is manufactured from a cubical piece, intended for a balance with an upper scale, divided into an upper and a lower guide bar by a horizontal opening extending all the way through it so that the spring body also forms the parallel guide for the balance scale, and which has wire strain gauges at thin spots in the areas of at least one guide bar the width of the spring body is divided at least in the area of the guide bars into two partial areas by a vertical opening which extends all the way through it and does not contact the edge. The vertical opening can have various shapes. The wide spring body has the advantages of in sensitivity to errors caused by off center loading and allowing the scale to be connected to the parallel-guided part of the spring body at two or three points, which reduces the stability requirements of the scale. The strain gauge are advantageously distributed so that one half of them is on each of the two areas of spring body.

Abstract: There is disclosed an axially folded tubular filter element for the filtration of fluids. The ends of the radially extending folds are in abutment at the internal folds with a support core and in abutment at the externally facing folds internally with an outer support grid. The support has a plurality of perforations. The ends of the tubular filter element are enclosed by a cap which encloses the ends of the tubular filter element in a sealing manner. The outside of the support core which supports the internally facing fold edges has a series of outwardly extending corrugated sections with rounded corrugated outwardly extending ridges, and the said perforations are located in the valleys of the corrugations. The corrugated structure extends in a longitudinal direction, is relatively flat and runs in a circumferential direction. A drainage pathway is also supplied along the outer surface of the support core.

Abstract: A filter consisting of connected upper housing and lower housing parts and a hydrophobic flat filter disc for gas filtration sandwiched therebetween, intended in particular for an exchange between a container such as a liquid reservoir partially filled with liquid and the surrounding atmosphere. The upper housing part includes an integral channelled filter support having channels for communication into a gas inlet-outlet means of the said upper housing part. The lower housing part includes an integral, channelled filter support having channels for communication into a centrally disposed bore located at a right angle to the filter support and empties into the gas area of a liquid reservoir for instance. The filter support is constructed to prevent liquid from completely blocking the hydrophobic filter disc.The filter support of the lower housing forms a planar plane with an annular channel therein and a series of radially extending channels terminating at a centrally located bore.

Abstract: A cardioplegic controlling and regulating device for the dosed perfusion of cardioplegic perfusion solution in open-heart surgery has a storage container for receiving the cardioplegic solution, which container is part of a scale and can be connected to the heart over a tubular conduit. A pressure-controlled dosing pump which acts on the tubular conduit and cooperates with a second, reversible pump which is constructed as an exhaust pump and is selectively operable synchronously or asynchronously within controllable tolerance limits with the first dosing pump during the perfusion and sustaining of the perfusion. An ultrafilter for the mixture of blood and cardioplegic solution removed from the patient's heart is located in a removal line. An outlet for the blood separated form the ultrafilter is connected by a conduit to a blood storage container and the permeate or filtrate outlet of which ends in a filtrate line or in a filtrate collector vessel.

Abstract: In a filtration apparatus for fluids and liquids having an external vessel, in particular a centrifuge tube and a filter unit disposed in the liquid, the medium to be filtered is under excess pressure and in contact with the filter element of the filter unit and for the static membrane filtration on the outer side of the filtration unit facing the vessel bottom a filter membrane is arranged with the filtration-active layer towards the outside.

Abstract: In an electromagnetic balance based on the principle of the eletromagnetic compensation of force a weight-proportional counterforce is generated by a current-carrying coil in a permanent magnet system. An arrangement with annular coil with vertical axis and with a permanent magnetic system constructed symmetrically to the central plane of the coil has proven to be advantageous. However, this arrangement results in a relatively great construction height of the balance. In order to decrease this height, the invention suggests that the soft iron pole plate which is usually present between the like poles of the plates of active magnetic material be reduced in its diameter or entirely eliminated and that the coil be allowed to extend into this area between the plates of active magnetic material. This in conjunction with the use of materials having high coercivity makes a very low constructional height possible.

Abstract: An electric inclination meter is built into a high-resolution electric balance with a measured value receiver, a microprocessor for digital signal processing and with a digital display. This inclination meter compensates the inclination-dependent errors of the balance. The inclination meter can have a movable suspended mass or it can have a container which is partially filled with liquid, thus forming a gas bubble. The positional deviation of the movable elements can be picked up optically or inductively.

Abstract: An apparatus for static membrane filtration, including a cylindrical sample vessel containing a filtration medium and subjected to centrifugal acceleration. A plunger is mounted in sealed manner in the sample vessel, and is being movable therein. An asymmetrical membrane is attached at the end of the plunger facing the bottom of the sample vessel, with the filtration active side of the membrane facing towards the outside. The bottom of the sample vessel is provided with a sealable opening. The mean density of the plunger is greater than the density of the filtration medium, and the length of the plunger in cm is greater or equal to the reciprocal of the mean plunger density in g/cm.sup.3 reduced by 1.

Abstract: A correction of temperature errors of the measured value receiver is generally necessary in high-resolution electronic balances. This can be accomplished in a known manner by directly influencing the measured value receiver with the aid of an analogous temperature sensor or by digitizing the output signal of the temperature sensor in a digitizer on the output side and performing the correction in the digital signal processing part. The invention has the task of indicating a circuit which permits the high-resolution digitizer which is present in the balance in any case to be used for digitizing the temperature signal without diminishing its preciseness. A switch (25 in FIG. 1) is provided to this end which feeds the output signal of a temperature sensor (27) to the input of the digitizer (15) in addition to the signal of the measured value receiver (1 . . . 13) at certain times controlled by the digital signal processing unit (22).

Abstract: In conventional fluorescent signaling devices the filament is fed with 50 Hz alternating current and the multiplex frequency of the signal ranges similarly in the area of 50 Hz, so that brightness variations occur with the difference in frequencies. A simple means for avoiding disturbing effect is the circuit of the present invention which divides the heating alternating current voltage into several stages and connects the negative terminal of the supply voltage of the fluorescent signaling device to one of the intermediate stages of the heating alternating current voltage depending on the signaling point that at the instant concerned happens to be lighted.

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: 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: A filtration or diffusion cell, consisting of adjacent facing support plates and cut diaphragm sections of a semi-permeable diaphragm, for the treating fluids. The support plates are sealed by stringlike or bandlike sealing elements for the separate flow conduction of the fluids. Support plates are provided with channel grooves, for holding the sealing elements. The channel grooves are open toward the plate plane and are provided with perforations through which a sealing material inserted in a flowable state and solidified in the grooves. Several support plates are connected by the sealing material to form a plate holder-like unit, and form seals for separate flow conduction. The support plates are square-shaped, and the front side and the back side of the cut diaphragm sections are subjected to crosswise flow of the fluid. The cut diaphragm sections are supported by grooves and groove crests extending in flow direction of the support plates.

Abstract: There is disclosed tubular filter element for the filtration of fluids, which is equipped with an enclosing housing with an inlet and outlet or is insertable into such a housing. The filter element is cylindrical and consists of a plurality of pleated radially extending folds. The filter is built up in several layers and the junction is bridged through at least one flexible connecting blank of synthetic material engaging between two layers and durably connected tight against leakage cohesively or adhesively by two seams or connecting zones. The flexible connecting blank by having a section extending between longitudinal edge portions of junction form an open fold pointing radially outwardly and a fold web pointing radially inwardly of the filter element.

Abstract: In an electromechanical weigher to be used in areas subject to explosion hazards, the electronic indicator ledge and the weigher apparatus or weighing system is constructed explosion proof in an intrinsically safe manner, and the power supply in the case is on all sides partitioned by means of bulkheads, and the free space enveloping these constituents is filled with an explosion-impeding granulate e.g. of quartz. For the use as dosing weigher for prescription weighings in such areas subject to explosion hazards, the indicator ledge is constructed by means of a hollow support engaging the case above the weigher dish and above a tare vessel of the usual height to be put on the weigher dish, as horizontal indicator constituent running approximately parallel to the weigher back, and the indicator constituent is tiltable at the support about a horizontal shaft in which structure the electric supply lines are passed from the indicator edge through the hollow support, into the inside of the case.

Abstract: The invention relates to a filtration apparatus with an upper casing part and a base part, each provided with a fluid chamber and an inlet or outlet respectively, for holding a flat filter plate cut to size which is enclosed between a permeable filter support associated with at least one casing part, and the other casing part, in which structure the two casing parts with inclusion of the flat filter plate cut to size are in the edge area sealed against each other in a leakproof manner and are connected by detachable tightening means.

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.