I Basic Tools for Transducer Modeling.- 1 Introduction.- 2 System Models.- II Transduction Mechanisms.- 3 Transduction Based on Changes in the Energy Stored in an Electric Field.- 4 Transduction Based on Changes in the Energy Stored in a Magnetic Field.- 5 Piezoelectricity and Pyroelectricity.- 6 Linear Inductive Transduction Mechanisms.- 7 Transduction Based on Changes in the Energy Dissipated.- 8 Optomechanical Sensors.- III Analysis of Transducers.- 9 2-port Theory.- 10 Response Characteristics.- 11 Practical Considerations.