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Standard Test Method for On-Line pH Measurement of Water of Low Conductivity
Automaticky přeložený název:
Standardní zkušební metoda pro On-Line měření pH vody o nízkou vodivostí
NORMA vydána dne 1.1.2014
Označení normy: ASTM D5128-14
Poznámka: NEPLATNÁ
Datum vydání normy: 1.1.2014
Kód zboží: NS-29937
Počet stran: 11
Přibližná hmotnost: 33 g (0.07 liber)
Země: Americká technická norma
Kategorie: Technické normy ASTM
Keywords:
high purity, low conductivity, on-line, pH, calculated pH, ICS Number Code 71.040.50 (Physicochemical methods of analysis)
Significance and Use | |||
5.1 Continuous pH measurements in low conductivity samples are sometimes required in pure water treatment using multiple pass reverse osmosis processes. Membrane rejection efficiency for several contaminants depends on pH measurement and control between passes where the conductivity is low. 5.2 Continuous pH measurement is used to monitor power plant cycle chemistry where small amounts of ammonia or amines or both are added to minimize corrosion by high temperature pure water and steam. 5.3 Conventional pH measurements are made in solutions that contain relatively large amounts of acid, base, or dissolved salts. Under these conditions, pH determinations may be made quickly and precisely. Continuous on-line pH measurements in water samples of low conductivity are more difficult 1.1 This 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 Sample |
Sample |
Sample |
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 |
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
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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.
Standard Specification for Reagent Water |
|
Standard Terminology Relating to Water (Includes all amendments and changes 2/14/2024). |
|
Standard Test Method for pH Measurement of Water of Low Conductivity |
|
Standard Practice for Handling of High Purity Water Samples |
|
Standard Guide for On-Line Monitoring Systems for Water Analysis |
|
Standard Practice for Determination of Precision and Bias of Applicable Test Methods of Committee D19 on Water |
|
Standard Test Methods for pH of Water |
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