EPA-NERL: 120.1:  Conductance by Conductivity Meter

  • Summary
  • Analytes
  • Revision
  • Data and Sites
Official Method Name
Conductance (Specific Conductance, umhos at 25oC)
Current Revision
Issued 1971; Editorial Revision 1982
Resistor Network
Method Subcategory
Method Source
  Methods for the Chemical Analysis of Water and Wastes (MCAWW) (EPA/600/4-79/020)
Brief Method Summary
The specific conductance of a sample is measured by use of a self-contained conductivity meter, Wheatstone bridge-type, or equivalent. Samples are preferable analyzed at 25oC. If not, temperature corrections are made and results reported at 25oC.
Scope and Application
This method determines conductance of drinking, surface, and saline water, domestic and industrial wastes and acid rain (atmospheric deposition).
Applicable Concentration Range
Not Available.
Turbidity: Since very slight amounts of turbidity interfere with the determination, samples must be filtered before analysis.
Quality Control Requirements
Sample Handling
Analyses can be performed either in the field or laboratory. If analysis is not completed within 24 hours of sample collection, sample should be filtered through a 0.45 micron filter and stored at 4oC. Filter and apparatus must be washed with high quality distilled water and pre-rinsed with sample before use.
Maximum Holding Time
24 hours, unpreserved.
28 days, preserved (MCAWW, Table 1).
Relative Cost
Less than $50
Sample Preparation Methods