Due to many applications of these systems in industry
and research, there is a strong interest in improving their
performance in terms of speed and accuracy, especially
for dynamic purposes. In order to simplify the design process
of a load cell to reach the desired global characteristics
in the best and fastest way, a small set of parameters
describing the main dynamic properties is needed. This
set of parameters may also be used to characterise existing
load cells in terms of applicability for dynamic purposes
and to determine controller parameters. From the area of
acoustics and sound engineering, a method for describing
the dynamic behaviour of electrodynamic speakers with
a set of parameters, called Thiele–Small parameters (TSP)
is known [1–3]. These parameters can be derived from
the characteristic curve of the frequency response of the
impedance of an electrodynamic speaker. They give
information on the mechanical and the electrodynamic
behaviour. By interpreting the TSP, the speakers can be
classified in their applicability as woofer (low frequency)
or tweeter (high frequency), the mechanical, electrical and
total quality factors are given, and a suitable form for a
loudspeaker box can be defined. The model applied to
determine the TSP reduces an electrodynamic speaker
without box to a mechanical system of spring, mass and
damper coupled to an electrical series circuit of ohmic
resistance and inductance. We show that an EMC load cell
may be reduced to a model of the same kind. Thus a set of
similar parameters describing the dynamic behaviour of an
EMC load cell can be found from its frequency response of
the impedance.