Dual Slope ADC Based on a Hydraulic Cylinder as an Integrator

The possibility of creating dual slope ADC, in which a hydraulic cylinder as an integrator is used, is shown on the example of devices proposed by the author. The work of the weight measuring device with calculation of the value of the weighed product and the device for converting the weight force into a time interval is considered. The transformation equations of these devices are derived. It is shown that the values of the parameters of the elements and blocks included in the device should not necessarily have strict constancy in time. This means that their change under the influence of temperature or any other reason does not lead to a significant measurement error. Nor do changes in the density of the working fluid for any reason cause measurement errors. It follows that when using the hydraulic cylinder as an integrator in the dual slope ADC neither the material from which the hydraulic cylinder is made, nor its initial geometrical dimensions and their constancy in time under the influence of external factors, nor the working fluid is not subject to any special requirements. In both considered devices, the hydraulic cylinder, as well as the devices in general, are simple and cheap, but allow to make measurements with sufficiently high accuracy.