Scope of strain gauge amplifiers
Depending on the type, strain gauge amplifiers come with several separate signal inputs to which the individual strain gauges are connected. The most common configuration is 4 to 6 inputs for 4 to 6 load cells. The amplifier generates the electric pulses that are then translated by an A/D converter and sent to the control unit. External amplifiers enable operators to adjust the output signal to the required format, which is one of their main advantages. Display modules and PCs can be controlled by means of measuring software through RS485 interfaces. The analogue output signal can be processed by a PLC unit. Some amplifiers provide signals suitable for field bus systems such as Profibus and ProfiNet.
Summary and conclusion
Strain gauge amplifiers do not only make the measurements from the strain gauge available to the control unit in a format that suits its logic, they also allow for the integration of strain gauges into bus systems. In addition, they can transmit signals over larger distances, so that the measurements can be processed by evaluation systems located away from the actual weighing or force measuring equipment.