Sensors for Mechatronics, 2nd Edition

Appendix B

Relations between quantities

B.1 Generalized equations

In Chapter 2, Sensor fundamentals, a classification of quantities based on thermodynamics is presented. Here we review the basic equations extended with the magnetic domain.

The first law of thermodynamics is:

$\text{d}Q=\mathrm{\Theta }\text{d}\sigma$ (B.1)

(B.1)

with Θ is the absolute temperature and dσ is the increase in entropy of the system. According to the second law of thermodynamics the energy content of an infinitely small volume of an elastic dielectric material changes by adding or extracting heat dQ (J) and by work dW (J) exerted upon it

$\text{d}U=\text{d}Q+\text{d}W\text{(J)}$ (B.2)

(B.2)

The work dW is the sum of the different ...