A cantilever operated vibrating thin strip for sensing pneumaticpressure

摘要

This paper proposes a pneumatic pressure sensor along with amicroprocessor-based signal processing and indicating instrument. A thinstrip in the form of a cantilever is attached to a diaphragm facing apneumatic medium on other side. The strip traverses through a pivotedhinge whenever pressure on the diaphragm is changing. The microprocessorexcites the strip for producing mechanical oscillations, through anelectromagnet and reads the oscillations of the strip from anoptocoupler. The fundamental frequency of vibration is then estimated bysoftware. As the frequency of oscillation depends on the length of thestrip extending beyond the hinge, the microprocessor determines theinstantaneous length of the strip and the pressure acting on thediaphragm, from the frequency measured. The proposed instrument has moresensitivity compared to the conventional pressure meters. Also, this hasmore durability compared to the previous vibrating wire transducer