Investigation of a small force standard with the mass based method

Abstract

A small force standard with the mass based method is developed. It is composed of an electromagnetic compensation balance, a nano-positioning stage and a displacement and pitch angle adjustment unit. The small force standard is used to measure spring constants of cantilevers in Atomic Force Microscope (AFM) and forces of small force transducers in related applications. Since the balance and the nano-positioning stage are traced to mass and length standards, respectively, the small force standard is SI traceable. The principle and structure of the small force standard and its main components are discussed in detail. The spring constants of several cantilevers used in AFM were calibrated by the small force standard. The calibration results are demonstrated and uncertainties are evaluated. For verifying metrological characteristics of the small force standard, a preliminary international comparison between NIM, PTB and KRISS was carried out. The comparison results were in good agreement and indicate that the calibration capabilities of the participating small force standards were equivalent within their reported uncertainties.