Abstract: An improved method and related apparatus for linearizing and spanning of the output from transducer systems such as load cells and the like. The method and system provide for deriving a constant that only requires calibration at mid-scale and full scale loads. The constant can thereafter be used in equations which correct subsequent data for nonlinearity and span so that the transducer system displays data in absolute units for all readings from zero to full scale.

Abstract: Load cells for weighing scales are provided with integrally formed flexures for preventing extraneous moments from affecting strain gauges secured to the load cells. The load cell itself includes in its simplest form a rectangular shaped body having cut-outs defining load carrying upper and lower arms and a vertical leg. Recessed areas are provided on opposite sides of the rectangular body between the upper and lower cut-outs to define a shear web to which strain gauges are attached. Flexure webs formed between the cut-outs in combination with further flexure webs formed at one of the ends of the load cell body effect the desired isolation.

Abstract: The conversion is effected by adding equal and opposite reference voltages to the analog signal to provide two first output voltage levels. The voltage difference between these levels is converted into a first given number of pulses. The polarity of the analog signal is then reversed during the second half of the cycle so as to be subtracted from the reference voltages for providing two second output voltage levels. The voltage difference between these levels is converted into a second given number of pulses. A function of the first and second number of pulses provides a numerical count directly proportional to the analog signal and because of the bipolar operation; that is, the switching of the polarity of the analog input signal, all zero drift is eliminated.

Abstract: The scale includes a horizontal load plate and base plate supported in spaced parallel relationship by first and second generally rectangular load members lying in vertical spaced planes extending between the corners of the load plate and base plate. Opposite end portions of each rectangular load member are symmetrical about a vertical axis passing midway therethrough, these opposite end portions defining corner flexure supports connected between central body portions of the rectangular load members and end posts. The end posts connect to the load plate and the bottom of the central body portions of the members rest on the base plate. Each corner flexure support means includes specially designed flexure webs which will flex under a load on the base plate. Strain gauges attached to certain ones of the flexure webs provide electrical read-out signals constituting a function of a force applied to the load plate.

Abstract: The amplifier system comprises a pair of operational amplifiers with an appropriate resistance network such that when a reference voltage and differential signal are applied to the system, changes in the gain of the amplifier system will only change the gain of the differential signal and will not affect the reference voltage.

Abstract: Short term creep compensation for load cells, platform scales, bench scales and the like is achieved by introducing a thermo-couple in series with one of the output leads from the load cell and utilizing an amplified output signal derived from the original output signal to generate heat which is transferred to a terminal or both terminals of the thermo-couple. The thermo-couple provides a compensating signal which is equal and opposite to the output drift resulting from the creep characteristics so that the final output signal is fully compensated. Proper generation of the compensating signal can be controlled by the gain of the amplifier, polarity of the input signal to the amplifier, and the transfer characteristics from the heater to the thermo-couple terminal.

Abstract: Horizontally loaded load cells are isolated by using an integrally formed flexure in the load cell body. Two or more of these cells can be secured to a platform to form a platform scale and the flexure isolation prevents the introduction of interaction terms resulting from extraneous torsion forces or moments from off-center loading on the platform.

Abstract: Horizontally loaded load cells are isolated by using an integrally formed flexure in the load cell body. Two or more of these cells can be secured to a platform to form a platform scale and the flexure isolation prevents the introduction of interaction terms resulting from extraneous torsion forces or moments from off-center loading on the platform.

Abstract: The sensitivity of two or more load elements and associated strain gauges supporting a platform are equalized by the progressive removal of material at a location which essentially changes the rigidity of the securement of one of the load elements and its associated strain gauges until equalization results. By making the sensitivities of all of the load elements and their associated strain gauges the same, the output signal reading indicating a load will be the same for center and off-center positions of the load on the platform.

Abstract: The load cell comprises a flat disc having an inner portion and outer ring integrally connected together by flexure webs at spaced circumferential points, the disc having holes drilled in its side to enable the sensitivity of strain gauges secured to the webs to be equalized. Upper and lower flat diaphragms sandwich the disc, the diaphragms being secured only to the top and bottom surfaces of the outer ring and to central areas of the inner portion. A platform above the upper diaphragm is secured to a central portion of this diaphragm. The assembly is completed by a circular base supporting the under peripheral portion of the lower diaphragm. The strain gauges attached to the flexure webs provide signals upon axial movement of the inner portion relative to the outer ring in response to a weight or load on the platform.