ASTM D 5128 : 2014

Name: ASTM D 5128 : 2014
Brand: ASTM
Price: 135.86 AUD

Superseded

View Superseded by

Standard Test Method for On-Line pH Measurement of Water of Low Conductivity

Available format(s)

Hardcopy , PDF

Superseded date

10-12-2022

Language(s)

English

Published date

14-02-2014

Publisher

American Society for Testing and Materials

1.1This test method covers the precise on-line determination of pH in water samples of conductivity lower than 100 μS/cm (see Table 1 and Table 2) over the pH range of 3 to 11 (see Fig. 1), under field operating conditions. pH measurements of water of low conductivity are problematic for conventional pH electrodes, methods, and related measurement apparatus.

TABLE 1 Calculated Conductivity and pH Values at 25°C of Low Concentrations of NaOH in Pure Water ^A

Note 1—This table tabulates the theoretical conductivity and pH values of low levels of NaOH in pure water as calculated from available thermodynamic data.

Note 2—To illustrate the high sensitivity of the sample pH at these low concentrations to contaminants, the last column lists errors that would result if the sample were contaminated with an additional 1 mg/L through sample or equipment handling errors.

Sample Concentration, mg/L	Sample Conductivity, μS/cm	Sample pH	Δ pH Error from Additional 1 mg/L NaOH Contaminate
0.001	0.055	7.05	Δ 2.35
0.010	0.082	7.45	Δ 1.95
0.100	0.625	8.40	Δ 1.03
1.0	6.229	9.40	Δ 0.30
8.0	49.830	10.30	Δ 0.05

^A Data courtesy of Ref (1).^B This data developed from algorithms originally published in Ref (2).

^B The boldface numbers in parentheses refer to a list of references at the end of this standard.

TABLE 2 Calculated Conductivity and pH Values at 25°C of Low Concentrations of HCl in Pure Water ^A

Note 1—This table tabulates the theoretical conductivity and pH values of low levels of HCl in pure water as calculated from available thermodynamic data

Sample Concentration, mg/L	Sample Conductivity, μS/cm	Sample pH	Δ pH Error from Additional 1 mg/L HCl Contaminate
0.001	0.060	6.94	Δ2.38
0.010	0.134	6.51	Δ 1.95
0.100	1.166	5.56	Δ 1.03
1.0	11.645	4.56	Δ 0.30
8.0	93.163	3.66	Δ 0.05

^A Data courtesy of Ref (1). This data developed from algorithms originally published in Ref (2).

FIG. 1 Restrictions Imposed by the Conductivity pH Relationship

1.2This test method includes the procedures and equipment required for the continuous pH measurement of low conductivity water sample streams including the requirements for the control of sample stream pressure, flow rate, and temperature. For off-line pH measurements in low conductivity samples, refer to Test Method D5464.

1.3The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4This 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.

Committee	D 19
DocumentType	Test Method
Pages	11
PublisherName	American Society for Testing and Materials
Status	Superseded
SupersededBy	ASTM D 5128 : 2014 : R2022
Supersedes	ASTM D 5128 : 2009

ASTM D 1193 : 2006 : R2018	Standard Specification for Reagent Water
ASTM E 2635 : 2014	Standard Practice for Water Conservation in Buildings Through In-Situ Water Reclamation
ASTM D 1293 : 2018	Standard Test Methods for pH of Water
ASTM D 5464 : 2016	Standard Test Method for pH Measurement of Water of Low Conductivity
ASTM D 6569 : 2014	Standard Test Method for On-Line Measurement of pH (Withdrawn 2023)
ASTM E 70 : 2019	Standard Test Method for pH of Aqueous Solutions With the Glass Electrode

ASTM D 1129 : 2003	Standard Terminology Relating to Water
ASTM D 3864 : 2006	Standard Guide for Continual On-Line Monitoring Systems for Water Analysis
ASTM D 1129 : 2013	Standard Terminology Relating to Water
ASTM D 1129 : 2013 : R2020	Standard Terminology Relating to Water
ASTM D 2777 : 2012	Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
ASTM D 1193 : 1977 : R1983 : EDT 1	Standard Specification for Reagent Water
ASTM D 5464 : 2011	Standard Test Method for pH Measurement of Water of Low Conductivity
ASTM D 1129 : 2006	Standard Terminology Relating to Water
ASTM D 4453 : 2002	Standard Practice for Handling of Ultra-Pure Water Samples
ASTM D 2777 : 2003	Standard Practice for Determination of Precision and Bias of Applicable Methods of Committee D-19 on Water
ASTM D 2777 : 2021	Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
ASTM D 2777 : 2013	Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
ASTM D 2777 : 1998	Standard Practice for Determination of Precision and Bias of Applicable Methods of Committee D-19 on Water
ASTM D 1129 : 1999 : REV A	Standard Terminology Relating to Water
ASTM D 1129 : 2006 : REV A	Standard Terminology Relating to Water
ASTM D 1193 : 2006 : R2011	Standard Specification for Reagent Water
ASTM D 1129 : 2003 : REV A	Standard Terminology Relating to Water
ASTM D 1129 : 2002	Standard Terminology Relating to Water
ASTM D 1293 : 1999	Standard Test Methods for pH of Water
ASTM D 4453 : 1991 : R1997	Standard Practice for Handling of Ultra-Pure Water Samples
ASTM D 1193 : 1991	Standard Specification for Reagent Water
ASTM D 1293 : 1999 : R2005	Standard Test Methods for pH of Water
ASTM D 1129 : 2004	Standard Terminology Relating to Water
ASTM D 2777 : 2008	Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
ASTM D 1293 : 2018	Standard Test Methods for pH of Water
ASTM D 2777 : 2006	Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
ASTM D 1129 : 2002 : REV A	Standard Terminology Relating to Water
ASTM D 4453 : 2017	Standard Practice for Handling of High Purity Water Samples
ASTM D 3864 : 2012	Standard Guide for On-Line Monitoring Systems for Water Analysis
ASTM D 1193 : 1970	Standard Specification For Reagent Water
ASTM D 1193 : 2006	Standard Specification for Reagent Water
ASTM D 4453 : 2002 : R2006	Standard Practice for Handling of Ultra-Pure Water Samples
ASTM D 5464 : 2007	Standard Test Method for pH Measurement of Water of Low Conductivity
ASTM D 1293 : 2012	Standard Test Methods for pH of Water
ASTM D 1193 : 1999	Standard Specification for Reagent Water
ASTM D 1129 : 2010	Standard Terminology Relating to Water
ASTM D 4453 : 2011	Standard Practice for Handling of High Purity Water Samples
ASTM D 1129 : 2006 : REV A : EDT 1	Standard Terminology Relating to Water
ASTM D 1129 : 2001	Standard Terminology Relating to Water
ASTM D 1129 : 2004 : EDT 1	Standard Terminology Relating to Water
ASTM D 5464 : 1993 : R2001	Standard Test Methods for pH Measurement of Water of Low Conductivity
ASTM D 5464 : 2016	Standard Test Method for pH Measurement of Water of Low Conductivity
ASTM D 1193 : 2006 : R2018	Standard Specification for Reagent Water
ASTM D 2777 : 2008 : EDT 1	Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water
ASTM D 3864 : 1996 : R2000	Standard Guide for Continual On-Line Monitoring Systems for Water Analysis
ASTM D 1293 : 1984 : R1990	Standard Test Methods for pH of Water
ASTM D 4453 : 2016	Standard Practice for Handling of High Purity Water Samples