This book chapter aims to give an overview of the wide range of techniques available to measure forces. The most common measurement principles of force transducers are introduced with special focus on strain gauge load cells and piezoelectric crystal force transducers. Furthermore, the characteristics of force measurement systems are discussed, as well as the importance of calibration.

Chapter Contents:

• 3.1 Force measurement systems
• 3.1.1 Principles of force transducers
• 3.1.1.1 Elastic deformation with resistance measurement
• 3.1.1.2 Elastic deformation with displacement measurement
• 3.1.1.3 Inverse magnetostrictive effect
• 3.1.1.4 Piezoelectric effect
• 3.1.1.5 Electromagnetic force compensation
• 3.1.2 Differential Lorentz force eddy current testing sensor
• 3.1.3 Characteristics and calibration of force measurement systems
• 3.2 Optimization of PM systems
• 3.2.1 Introduction and motivation
• 3.2.2 Methods
• 3.2.2.1 Problem definition
• 3.2.2.2 Magnet system and design variables
• 3.2.2.3 Scaling parameters
• 3.2.2.4 System parameters
• 3.2.2.5 Objective function
• 3.2.2.6 Definition of constraints
• 3.2.2.7 Optimization strategies
• 3.2.2.7.1 Volume and force constraint optimization
• 3.2.2.7.2 Volume adaptive force constraint optimization
• 3.2.2.8 SQP algorithm
• 3.2.2.9 Objective and constraint function evaluation
• 3.2.2.9.1 Step 1: Primary magnetic flux density (2D)
• 3.2.2.9.2 Step 2: Induced eddy currents in the conductor free of defects (3D)
• 3.2.2.9.3 Step 3: Induced eddy currents in the conductor with defect (3D)
• 3.2.3 Optimization results and discussion
• 3.2.4 Prototypes of optimized LET magnet systems
• 3.2.5 Defect depth study
• 3.2.6 Conclusions

Inspec keywords: electromagnetic forces; force sensors; strain gauges; inductive sensors; piezoelectric transducers; reviews; eddy current testing; calibration

Other keywords: piezoelectric crystal force transducers; motion-induced eddy current techniques; calibration; MIECT sensors; strain gauge load cells; force transducers; force measurement systems; overview

Subjects: Sensing devices and transducers; Sensing and detecting devices; Mechanical variables measurement; Reviews and tutorial papers; resource letters; Materials testing; Magnetic instruments and techniques; Measurement of mechanical variables; Measurement standards and calibration; Piezoelectric devices; Measurement standards and calibration; Electrical instruments and techniques