ASTM D6698-01

Standard Test Method for On-Line Measurement of Turbidity Below 5 NTU in Water

SCOPE
1.1 This test method is applicable to the on-line measurement of turbidity under 5 nephelometric turbidity units (NTU) in water.
1.2 It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.
1.3 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.

General Information

• Status: Historical
• Publication Date: 09-Jul-2001
• ICS: 13.060.60 - Examination of physical properties of water
• Technical Committee: D19 - Water
• Drafting Committee: D19.03 - Sampling Water and Water-Formed Deposits, Analysis of Water for Power Generation and Process Use, On-Line Water Analysis, and Surveillance of Water

Relations

• Replaced By: ASTM D6698-07 - Standard Test Method for On-Line Measurement of Turbidity Below 5 NTU in Water
• Effective Date: 15-Jun-2007
• Referred By: ASTM E2635-22 - Standard Practice for Water Conservation in Buildings Through In-Situ Water Reclamation
• Effective Date: 10-Jul-2001
• Referred By: ASTM D4188-17 - Standard Practice for Performing Pressure In-Line Coagulation-Flocculation-Filtration Test in Water
• Effective Date: 10-Jul-2001
• Referred By: ASTM D7285-06(2017) - Standard Guide for Recordkeeping Microfiltration and Ultrafiltration Systems
• Effective Date: 10-Jul-2001
• Referred By: ASTM D7726-11(2016)e1 - Standard Guide for The Use of Various Turbidimeter Technologies for Measurement of Turbidity in Water
• Effective Date: 10-Jul-2001
• Referred By: ASTM D7725-17 - Standard Test Method for the Continuous Measurement of Turbidity Above 1 Turbidity Unit (TU)
• Effective Date: 10-Jul-2001
• Referred By: ASTM D6908-06(2017) - Standard Practice for Integrity Testing of Water Filtration Membrane Systems
• Effective Date: 10-Jul-2001
• Referred By: ASTM D4410-16 - Terminology for Fluvial Sediment
• Effective Date: 10-Jul-2001

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D6698–01
Standard Test Method for
1
On-Line Measurement of Turbidity Below 5 NTU in Water
This standard is issued under the fixed designation D 6698; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope US Patent 4,283,143 fromAdvanced Polymer Systems, Inc.,
123 Saginaw Dr., Redwood City, CA 94063
1.1 This test method is applicable to the on-line measure-
US Patent 4,291,980 fromAdvanced Polymer Systems, Inc.,
ment of turbidity under 5 nephelometric turbidity units (NTU)
123 Saginaw Dr., Redwood City, CA
in water.
US Patent 5,777,011 from Hach Company, 5600 Lindbergh
1.2 Itistheuser’sresponsibilitytoensurethevalidityofthis
Drive, Loveland, CO 80537
test method for waters of untested matrices.
1.3 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Definitions—For definitions of terms used in this
responsibility of the user of this standard to establish appro-
method refer to Terminology D 1129.
priate safety and health practices and determine the applica-
3.2 Definitions of Terms Specific to This Standard:
bility of regulatory limitations prior to use.
3.2.1 calibration turbidity standard—a turbidity standard
2. Referenced Documents that is traceable and equivalent to the reference turbidity
2
standard to within statistical errors, including commercially
2.1 ASTM Standards:
prepared 4000 NTU Formazin, stabilized formazin, and sty-
D 1129 Terminology Relating to Water
renedivinylbenzene (SDVB). These standards may be used to
D 1193 Specification for Reagent Water
calibrate the instrument.
D 1889 Test Method for Turbidity in Water
D 2777 Practice for Determination of Precision and Bias of
NOTE 1—Calibration standards may be instrument specific.
Applicable Methods of Committee D19 on Water
3.2.2 calibration verification standards—defined standards
D 3370 Practices for SamplingWater from Closed Conduits
used to verify the accuracy of a calibration in the measurement
D 3864 Guide for Continual On-line Monitoring for Water
range of interest. These standards may not be used to perform
Analysis
calibrations, only calibration verifications. Included standards
2.2
are opto-mechanical light scatter devices, gel-like standards, or
EPA 180.1 Methods for Chemical Analysis of Water and
any other type of stable liquid standard.
Wastes, Turbidity
NOTE 2—Calibration verification standards may be instrument specific.
Standard Methods for the Examination of Water and Waste-
water 2130B, 19th edition
3.2.3 in-situ nephelometer—a turbidimeter that determines
ISO 7027 (The International Organization for Standardiza-
the turbidity of a sample using a sensor that is placed directly
tion) for the Determination of Turbidity
in the sample. This turbidimeter does not require transport of
Hach Method 8195
the sample to or from the sensor.
GLI Method 2
3.2.4 nephelometric turbidity measurement—the measure-
ment of light scatter from a sample in a direction that is at 90°
with respect to the centerline of the incident light path. Units
1
This test method is under the jurisdiction of ASTM Committee D19 on Water
are NTU (Nephelometric Turbidity Units); when ISO 7027
and is the direct responsibility of Subcommittee D19.03 on Sampling Water and
technology is employed, units are FNU (Formazin Nephelom-
Water-Formed Deposits, Analysis of Water for Power Generation and Process Use,
On-Line Water Analysis, and Surveillance of Water.
etric Units).
Current edition approved July 10, 2001. Published November 2001.
3.2.5 ratio turbidity measurement—the measurement de-
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
rived through the use of a nephelometric detector that serves as
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on the primary detector and one or more other detectors used to
the ASTM website.
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D6698–01
compensate for variation in incident light fluctuation, stray causes negative interference. Dissolved material that imparts a
light, instrument noise, or sample color. color to the water may cause errors in pure photoelectric
3.2.6 reference turbidity standard—a standard that is syn- nephelometric readings (versus ratio photoelectric nephelom-
thesized reproducibly from traceable raw materials by the user. etric readings) unless the instrument has sp
...