Description
Our Dielectric Constant Setup is a laboratory experiment to
demonstrate to the students the concept of Dielectric Constant, its
measurement, measurement of Curie temperature.
Dielectric or electrical insulating materials are understood as
materials in which electrostic field can persist for long times.
Layers of such substances are commonly inserted into capacitors to
improve their performance, and the term dielectric refers
specifically to this application.
An electric field polarizes the molecules of dielectric, producing
concentrations of charge on its surface that create an electric
field opposed (antiparallel) to that of capacitor. This reduces the
electric potential. Considered in reverse, this means that, with a
dielectric, a given electric potential causes the capacitor to
accumulate a larger charge.
All ferroelectric materials have a transition point called the
Curie point (Tc). At T>Tc, the crystal does not exhibit
ferroelectricity, while for T
Description of the Experimental Set-up
1.Probes Arrangement, DEA**1
It has two individually spring loaded probes. The probes
arrangement is mounted in a suitable stand, which also holds
the sample plate. To ensure the correct measurement of sample
temperature, the RTD is embedded in the sample plate
just below the sample. This stand also serves as the lid of
temperature controlled oven. Proper leads are provided for
connection to Capacitance Meter and Temperature Controller.
2.DEC-Sample
Barium Titanate (BaTiO3)
3.Oven, DEO**1
This is a high quality temperature controlled oven. The oven has
been designed for fast heating and cooling rates, which enhances
the effectiveness of the controller.
4.Main Unit
The Set-up consists of two units housed in the same cabinet.
(i) Oven Controller
Platinum RTD (A class) has been used for sensing the temperature. A
Wheatstone bridge and an instrumentation amplifier are used for
signal conditioning. Feedback circuit ensures offset and linearity
trimming and a fast accurate control of the oven temperature.
(ii) Digital Capacitance Meter
This is a compact direct reading Instrument for the measurement of
capacitance of the sample.
The experiment is complete in all respect.
