Abstract: An electronic weighing apparatus is provided, including a self-contained calibration weight module that is operated by a motor to alternately connect and disconnect, respectively, a calibration weight relative to the vertically-displaceable parallelogram-guided load receiving member of the scale. The calibration weight is normally suspended in an inoperable condition by means of a pair of internally threaded sleeves rotatably supported in the cover portion of the housing of the calibration weight module. A motor is operable to rotate the sleeves and thereby lower lifting screws threadably connected therewith, whereby the calibration weight is lowered toward a supported position between and in engagement with a pair of parallel carrier arms that extend horizontally from the load receiver.

Abstract: A vessel holding device is composed of a sheet metal strip which is bent to form a polygon. The resulting side wall members are provided with bores or recesses for holding the vessels, such as, test tubes or syringe cylinders in a predetermined manner. The vessel holding device can be used standing on one of the side wall members or on the upper or lower edges of the device.

Abstract: A weighing apparatus comprising a first self-contained weighing device (1) including a first farme (2), a first load-receiving member (5) connected by a parallel guide arrangement for movement from a normal no-load position relative to the first frame, a load-responsive device (10) for indicating the magnitude of an applied load as a function of the movement of the first load receiving member, and a first motion-transmitting lever (7) connected between the first load receiving member and the position-responsive device, characterized by the provision of a second load receiving member (16,28) to which the load to be measured is applied, and a second pivotally mounted motion-transmitting lever (17,30) connecting the second load receiving member, thereby to provide a resultant load range that is higher than that of the first weighing device. Thus, various increased load ranges may be achieved starting from a standard self-contained weighing apparatus.

Abstract: A draft protection device for a precision balance including an exposed weighing dish. The device includes at least two hollow bodies of similar shape which can be telescopically slid one into the other. The hollow bodies are maintained in the desired position by a self-locking intermediate ring placed on the inner second hollow body.

Abstract: A coupling for transmitting a rotary motion in both directions of rotation. The coupling includes a drive shaft and a driven shaft and has a freewheeling capability in both directions of rotation for rotary motions introduced into the driven shaft. One or more balls are guided in a circular groove having an asymmetrical cross-section. The balls rest against a clamping disk having a non-circular cross-section. When the drive shaft is rotated, the balls are pressed against and clamped by a guide surface of the driven shaft.

Abstract: An electronic balance includes a measuring cell for electromagnetic load compensation. The measuring cell and a load receiving member of the balance are arranged in an inner housing which is closed to all sides with the exception of an opening for a receiving cone of the load receiving member. The inner housing is mounted in the balance housing so as to be spaced apart from the walls, the base and the cover of the balance housing. A circumferentially extending partition wall is tightly sealingly attached to the bottom and the cover of the balance housing. The partition wall is mounted between the inner housing and the walls of the balance housing.

Abstract: In a new method for the titrimetric determination of the contents in a chemical solution, wherein a quantity of a reaction component, corresponding in each case to the change of a certain physical-chemical magnitude or a value derived from that, is added to a reaction component and this added quantity is so regulated that it will be a function of the prior and/or predetermined magnitude change or changes and the already added total quantity of one of the reaction components. In the method mentioned, the minimum quantity added is not allowed to fall below a predetermined percentage, e.g., 1.0 percent, or even 0.5 to 0.1 percent, of the already added quantity. The apparatus for performing the method therefore contains devices operable to regulate the quantity to be added as a function of the magnitude change and the already added total quantity of one of the reaction components. Potentiometric titration is the most important area of application of the new determination method.

Abstract: The calibration process is initialized as a function of the past measurement results. The time to the next calibration is dependent on the quality of the calibrations in the past. Before the calibrating of the balance, the program checks a number of parameters, which can affect the weighing result and compares the results with predetermined limits. If set conditions are exceeded, the program in each case returns to the beginning and starts anew.

Abstract: The moving housing parts of an analytical balance are couplable with drive apparatus, which receives the appropriate control commands for opening or closing, for instance, from sensors operating in a contactless fashion. Proximity sensors or voice control sensors can be utilized as sensors. The mechanical process of the opening-or closing movement occurs by means of a drive housed in the housing.

Abstract: An apparatus for depositing of reference weights in an electronic scale consisting of two levers swivelable around vertical axes, one end of each lever is always in contact with a cam disc attached on a vertically disposed shaft and the other end of which is developed as a gliding shoe which may be pushed below the lifting tray. By rotating the cam shaft, the lifting trays cause the reference weights to be deposited by the cam discs at first each individually one after the other and then jointly onto the carriers.

Abstract: A weighing apparatus is provided with a wind shielding arrangement for protectively enclosing a load-receiving scale member. A plurality of symmetrical curvilinear concave transparent shell-like wind shield sections of unequal diameters of generation are concentrically mounted on the scale housing above the load-receiving pan for relative rotational movement about a common axis between a closed protective condition, and an open condition affording access to the scale pan. In one embodiment, a pair of shield sections have generally coplanar edge portions mounted in a pair of concentric circular grooves, respectively, contained in a support on the upper surface of the housing adjacent the load receiving member. The inner shield section is retained in its associated groove by a resilient annular retainer ring that extends radially outwardly above a radially inwardly extending lip portion on the lower edge of the inner shield section.

Abstract: A temperature sensor includes an elongated support of a material having good thermal conductivity. The temperature sensor element is pressed against the support by a spring element, in order to measure the temperature of the support. A mean temperature value can be determined, as a result of the substantial length of the support and the particular horizontal disposition thereof with respect to the heating element.

Abstract: Weighing apparatus of the electromagnetic load compensation type includes an improved variable (C.sub.x) and reference (C.sub.o) capacitance comparison arrangement for sensing the position of the movable load receiver member relative to the stationary base member. The comparison arrangement supplies an error signal that is proportional to the capacity ratio, which error is used to control a compensation current (i.sub.L) that is supplied to a compensation coil to maintain the movable load receiver member at its initial zero position. The variable capacitance is produced by a variable air capacitor including a first pair of stationary capacitor plate electrodes (10, 12), and a movable plate-like metal shield or screen which extends partially between the first pair of electrodes in accordance with movement of the load receiver member.The position sensor arrangement is simple to construct and install, and affords precise measurement during use.

Abstract: The force measuring apparatus includes a single-mode optical fiber having a defined anisotropy, whereby coherent light suppled to one end of the optical fiber is guided as two waves having linear orthogonal polarizations, respectively. The optical fiber is arranged between a pair of parallel planar pressure plates, the orientation of the optical fiber being such that the aforementioned linear polarizations are parallel with and normal to the remote surfaces of the pressure plates, respectively. Upon the application of a force to be measured in the compressive direction normal to one remote surface of a plate, a phase shift is produced between the waves which is a function of the magnitude of the load to be measured, as determined by interferometer means arranged at the other end of the optical fiber.

Abstract: Precision balance including a weighing dish supported by a support member which is guided by means of guide arms in such a way that weighing dish performs essentially a vertical movement during weighing. The spacing between the ends of the guide arms is effected by means of a differential screw which changes the width of a slot formed in the frame of the balance. A V-shaped insert is placed in the slot. The insert has linear contact with the sides of the slot. When the portion of the frame located above the slot is being bent by the differential screw, an exactly defined bending line is ensured.

Abstract: Weighing apparatus of the electromagnetic load compensation type is provided with a movable coil arranged in the air gap of a permanent magnet system, and which includes a load-compensation winding through which flows a load-dependent compensation current. As a temperature sensor for measuring the coil temperature, use is made of the coil, specifically, either the load winding itself or an additional winding that is in thermal contact with it. A resistance measuring device determines its temperature-dependent resistance from the voltage and the current on or in the winding. Accurate and real-time measurement of the coil temperature as a measure for controlling the compensation of its influence on the measurement reading is possible in this way.

Abstract: A precision balance in which the fastening surface (56) for an upper guide arm (22) is fastened to a housing (42) which, by means of a pair of parallel levers (48,50) is vertically movable along the side wall (24) of the balance (18). The movement is effected by means of an adjusting element which engages in a conical slot (60) defined between the upper movable portion of the housing (42) and a bearing face (64) which is arranged immovable relative to the balance (18).

Abstract: Buret apparatus of the type including a buret conduit terminating at one end in a siphon, characterized in that the siphon includes a siphon passage formed on a stopper that is removably mounted in the buret conduit. The improved siphon structure is relatively inexpensive to manufacture, and is less susceptible to breakage than the conventional circular glass siphon devices. The improved apparatus is particularly suitable for use as a precision titrator or dosing device where measurements in the microliter range are required.