Device for measuring physical quantities

摘要

A device for measuring physical quantities such as pressure, temperature and so forth is described, which has a sensor, the resistance value of which changes as a function of this quantity and which is connected in one arm of a measuring bridge, the bridge voltage of which is analog/digital-converted and is processed in a digital computing circuit. The device according to the invention is characterised by the combination of the following features: (a) the measuring bridge exhibits a null error so that the bridge voltage is always not equal to 0V, (b) the bridge voltage is applied to an integrator, the output connection of which is connected to a window comparator and which is reset when the upper window value is reached, and (c) the pulse output signal of the window comparator, the width of which is a measure of the quantity to be measured, is applied to an input connection of a microcomputer circuit which determines from this the physical quantity to be measured.