1.1 These test methods cover the determination of the electrical conductivity and resistivity of water. The following test methods are included: 1.2 These test methods have been tested in reagent water. It is the user's responsibility to ensure the validity of these test methods for waters of untested matrices. 1.3 For measurements below the range of these test methods, refer to Test Method D 5391. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 12.1 This test method is applicable to field and routine laboratory measurements of the electrical conductivity of water using static samples. 19.1 This test method is applicable to the continuous, in-line measurement of the electrical conductivity of water.