DESIGN AND DEVELOPMENT OF FORCE TRANSDUCERS FOR INDUSTRIAL APPLICATIONS

Abstract

The precise and accurate force measurement performs an extremely important job during a variety of industrial applications, which helps in quality control of the product development and to optimize different material synthesis processes, thus necessitating its precise and accurate measurement. From the investigation of global research, it is noticed that the majority of investigation linked to force measurement has been done to design and develop a variety of force transducers. A limited investigation has been made to talk about different facets of primary force standard as well as secondary force calibration machines.

With day by day growing technological demands of quality systems (ISO 9000/IS 14000) and call for more precise & accurate measurement of force for quality products, the force transducers are developed. Force transducers play a very significant role in maintaining uniformity in force measurements and proficiency testing within the country by providing unbroken chain of measurement traceability of force from primary force standard machines/force calibration machines to the uniaxial testing machines (UTM) of user industries and NABL accredited calibration laboratories. Although the force transducers have been developed related to various field applications, however the majority of the development has been regard to meet the demand of particular applications and barely any attention is given for development of force transducer to serve up as force transfer standards.

Considering the past research shortcomings into account, the present investigation aims to develop some force transducers intended for applications of static force measurement. The circular diaphragm shaped steel force transducers are developed on the basis of classical plate theory (CPT) of bending of circular plate and investigated for deflection and v stress/strain under action of centrally applied forces. Another very small MEMS circular diaphragm load sensor of silicon is developed on the basis of deflection theorem related to small MEMS sensors. Rigorous validations have been taken into account for the findings of analytical approach with the computational investigations e.g. finite element analysis. Deviations are found among the analytical and computational findings. The one of the elastic sensing element are fabricated of steel (EN24) by conventional technique, along with another very small elastic sensing element of silicon are fabricated through MEMS technology. Both the elastic sensing elements are strain gauged on the most suitable locations find out on the basis of FEM software. The strain gauges are then configured in a Wheatstone bridge circuit. The force transducers thus developed are then metrological characterized as per the calibration procedures based on standards like ISO-376 & IS- 4169 and their measurement uncertainty are evaluated.

The force transducer under reference will be of great importance both as force proving and measuring instruments for NABL accredited laboratories to maintain traceability to national force primary standard and for proficiency testing in the country. The present research will also enable the metrology personals to design, develop and metrological investigate the force transducers in a rationalized manner.