Dynamic measurement circuit for the resistive transducers

Abstract

This paper is focused on measurement of the resistive transducers used in dam's monitoring process. The hydro-energetic buildings, like dams are equipped with a large type of resistive transducer. Some of the sensors are placed inside during the dam construction, but, sensors are also mounted later on. The dams are monitored with a large type of resistive transducers. The first generations contain 40Ω and new sensor generations have 5k Ω. The main aim of this paper is to develop a measurement circuit that allows measuring all resistive sensors using the same circuit. The proposed circuit excites the transducer with a constant current. The signal acquisition is made with a programmable gain amplifier (PGA). The resistive transducer is measured in the useful range using a relative voltage on one of the PDA inputs. The relative voltage is generated with a digital analog converter (DAC). The measurement circuit it's a feedback complex structure. The measurement value is obtained sequentially in several steps. The central unit of measurement device is a microcontroller; the systematic error can be compensated soft. Through a careful selection of electronics components like resistors and reference voltages, the measurement accuracy is 0.1%.