Difference between revisions of "Permittivity and Permeability of Materials Obstacle Course"

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(Permittivity of a Lossless Material From a Capacitance Measurement)
(Permittivity of a Lossless Material From a Capacitance Measurement)
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# Place three samples (air, Teflon, glass) between the aligned and polished ends of two 3/8" diameter, 1/2" lengths of 6061 Al rods (as shown at right). <math>d</math> should be on the order of 1 mm. Measure the capacitances and, from the known surface area <math>A</math> and spacing <math>d</math>, determine the material's relative permittivity.  <math>C = \epsilon_r \epsilon_0 \frac{A}{d}</math>.
 
# Place three samples (air, Teflon, glass) between the aligned and polished ends of two 3/8" diameter, 1/2" lengths of 6061 Al rods (as shown at right). <math>d</math> should be on the order of 1 mm. Measure the capacitances and, from the known surface area <math>A</math> and spacing <math>d</math>, determine the material's relative permittivity.  <math>C = \epsilon_r \epsilon_0 \frac{A}{d}</math>.
 
# How do your measured permittivity values compare to standard reference values?
 
# How do your measured permittivity values compare to standard reference values?
 +
<math>\epsilon_r</math>(air): 1.000536<br>
 +
<math>\epsilon_r</math>(Teflon): 2.1<br>
 +
<math>\epsilon_r</math>(glass): 3.7-10<br>

Revision as of 13:09, 16 May 2018

PAGE UNDER CONSTRUCTION


Permanent Materials

- 6061 3/8" Al rod stock
- Teflon
- Glass microscope slide
- HP Signal Generator (DC-1 GHz)
- Oscilloscope (at least 1GHz bandwidth)
- Miscellaneous electrical components

Materials to Borrow When Necessary

- Milling machine
- Lathe

Activities

Reading

  1. Read the Wikipedia articles on permittivity and permeability. With the help of the instructor or TA try to achieve a physical understanding of just what the permittivity and permeability mean in a bulk material.
  2. Read the first three sections of this paper (pages 1-27). Pay particular attention to the permittivity () / capacitance and permeability () / inductance associations.

Permittivity of a Lossless Material From a Capacitance Measurement

Epsiloncap1.png
  1. Place three samples (air, Teflon, glass) between the aligned and polished ends of two 3/8" diameter, 1/2" lengths of 6061 Al rods (as shown at right). should be on the order of 1 mm. Measure the capacitances and, from the known surface area and spacing , determine the material's relative permittivity. .
  2. How do your measured permittivity values compare to standard reference values?

(air): 1.000536
(Teflon): 2.1
(glass): 3.7-10