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.