Signal processing and error reduction for reciprocating triboelectrometry

Overview & Synopsis

The measurement of the friction coefficient is essential to numerous applications, including mechanisms and tribocharging assessments. There are several families of measuring devices using various measuring principles, configurations and types of movements. We analyze in detail the potential measurement error sources in the devices falling in one of these classes and exemplify these errors for the case of a custom-made device. The use of the method of the horizontally sliding cartridge (also named in the article sledge or shuttle) with vertical force applied to the probe, and of other similar setups for friction force and friction coefficient measurement raises several obstacles. Among these are the compensation of the effect of the involved masses and of the frictions between the cartridge and the measuring table, of the mass and frictions in the displacement sensor, moreover the estimation of the mechanical noise in the sliding process. We analyze the involved factors, exemplify the analysis with measured signals, propose a compensation method, and apply it to a measuring setup in order to reduce measurement errors. The analysis and the related method for error compensation are appropriate for and easily adaptable to a large class of measurement setups.