Salinity in Soil -- February, 2002



Teacher Hints:

  1. The conductivity sensor should be soaked in distilled water for 5 – 10 minutes before use to thoroughly wet the electrode.

  2. Electrical conductivity is the reciprocal of electrical resistance, which is measured in units of ohms (). Therefore the basic unit siemens (S) is the inverse of ohms (). To describe conductivity, the conductance of a material is measured between opposite faces of a 1-cm cube of the material -- or in a solution, between two electrodes 1 cm apart from each other. For more information, see the website "How Many? A Dictionary of Units of Measurement" at http://www.unc.edu/~rowlett/units/dictS.html

  3. Have your students review the ingredients of the potting soil to assist in determining why a difference may have occurred as compared to the dirt solution.