P8.9 - Applying and Measuring Small Forces

Event

SENSOR+TEST Conferences 2011
2011-06-07 - 2011-06-09
Nürnberg

Band

Proceedings SENSOR 2011

Chapter

P8 - Mechanical

Author(s)

N. Khélifa - Institut National de Métrologie, La Plaine Saint-Denis (France)

Pages

878 - 878

DOI

10.5162/sensor11/sp8.9

ISBN

978-3-9810993-9-3

Price

free

Abstract

Applying and measuring small forces is the final objective of our experiment described in a previous presentation. To apply a very small force in a controlled way, we need to know its point of application, direction and intensity. In this paper we describe a system constructed using piezoelectric actuators with a resolution at the nanometric level and flex plates made from HAVAR, a non-magnetic alloy.
At first, we report the results obtained with a similar system and suitable to be tested by using a commercial mass comparator having a resolution of 0.1 mg. The considered measuring method consists in application of the small forces generated by this apparatus alternatively on the plate of the balance and on the laser rod of a micro-force sensor based on photo-elastic effect. The results of measurement are then connected to that induced by putting calibrated mass on the top of the laser rod. The smallest mass standard used in mass metrology is now 100 mg and calibration of the optical sensor by deadweights appear to be the simple way. Generating and applying small forces, via the controlled deformation of a suitable piezoelectric actuator, tested in the range of 10-6 N (» 0.1 mg) to 5x 10-2 N (» 5 g), can be useful for the future photoelastic sensor for small forces measurement and dissemination.