ASTM D5391-99 - 10.6.1999
 
1. Scope

1.1 This test method covers the determination of electrical conductivity and resistivity of high purity water samples below 10 [mu]S/cm (above 0.1 Mohm-cm). It is applicable to both continuous and periodic measurements but in all cases, the water must be flowing in order to provide representative sampling. Static grab sampling cannot be used for such high purity water. Continuous measurements are made directly in pure water process lines, or in side stream sample lines to enable measurements on high temperature or high pressure samples, or both.

1.2 The values stated in SI units are to be regarded as the standard.

1.3 This standard does not purport to address all of the safety problems, 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.

 
2. Referenced Documents

D4519-25

Standard Test Method for On-Line Determination of Anions and Carbon Dioxide in High Purity Water by Cation Exchange and Degassed Cation Conductivity

D3864-12(2021)

Standard Guide for On-Line Monitoring Systems for Water Analysis

D3370-25

Standard Practices for Sampling Water from Flowing Process Streams

D2777-21

Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water

D2186-05

Standard Test Methods for Deposit-Forming Impurities in Steam

D1129-24

Standard Terminology Relating to Water

D1192-98

Standard Guide for Equipment for Sampling Water and Steam in Closed Conduits (Withdrawn 2003)

D1193-24

Standard Specification for Reagent Water

D1066-18(2025)

Standard Practice for Sampling Steam

D1125-23

Standard Test Methods for Electrical Conductivity and Resistivity of Water