Simulation of the analogue interface for remote measurements

This work is aimed at finding possibilities for increasing the accuracy of measurements and interfering analog interfaces for remote measurements using resistive strain gauges by introducing a new structural scheme, which is shown on the Fig. 1. It shows us the Schematic of the electrical functional analog interface for remote measurement using multiplexer and resistive strain gauges, which contains a measuring chain, a transmitter, the input of which is connected to a DC source through an analog demultiplexer, and the outputs of the measuring chain through the analog multiplexer are connected to the measuring amplifier, and a two-channel analog-digital converter with simultaneous sampling. The measuring chain is made in the form of three resistive current dividers, where one divider is formed by a resistive strain gauge and adjusting resistor, and two others – exemplary resistors. By introducing a new structural scheme, it will be possible to increase the accuracy of measurements and impedance of analog interfaces for remote measurements using resistive strain gauges. In this case, unlike the classical method of model measures, this method is distinguished by the «indistinguishability» of the measuring line, which makes it possible to compensate for a greater number of influential factors, in particular, the correlated noise of operational amplifiers and noise caused by the presence of the overall ground loop, the resistance of analogue switches and lines of communication. At the Fig. 2 we can see the electric model of the measuring channel in the software Elektronic Workbench. From the analysis of the simulation results it was found that the random additive component of the error would dominate. Since in the simulation of the only random component of the error there is a quantization error, the use of the differential method of measuring the output voltage will significantly improve the metrological characteristics.