ASTM D4940-98(2003)

Standard Test Method for Conductimetric Analysis of Water Soluble Ionic Contamination of Blasting Abrasives

SIGNIFICANCE AND USE
By-product abrasives manufactured from slags that are air cooled or quenched with pure water, normally contain low concentrations of ionic materials, as do mined mineral abrasives. However, slags quenched with seawater or other contaminated water, contain high amounts of ionic material as does seashore sand. This contamination of the abrasive can transfer to the steel surfaces being blasted, where it may accelerate corrosion. This test is useful in establishing the cleanliness of the abrasive at the jobsite.  
This test method provides a value that indicates the concentration of total water soluble ions based on their electrolytic mobility. Thus, it provides an indication of ionic corrosion potential.
Note 1—A typical value of conductivity for a high level of contamination is 500 μmho/cm. A typical value for a low level of contamination is 50μ mho/cm.
SCOPE
1.1 This test method describes a procedure for rapid evaluation of abrasives for the presence of ionic contamination by determining the total concentration of water soluble ionic contaminants by means of a conductivity test.
1.2 This test method does not identify the ionic species present nor provide quantitative results on each species.
1.3 This test method is based on a volume comparison among abrasives of similar sizes. A volume comparison is more closely related to surface area of the abrasives than is a weight comparison.
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.

General Information

• Status: Historical
• Publication Date: 09-Jan-2003
• ICS: 25.220.10 - Surface preparation
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.46 - Industrial Protective Coatings

Relations

• Replaces: ASTM D4940-98 - Standard Test Method for Conductimetric Analysis of Water Soluble Ionic Contamination of Blasting Abrasives
• Effective Date: 10-Jan-2003
• Replaced By: ASTM D4940-10 - Standard Test Method for Conductimetric Analysis of Water Soluble Ionic Contamination of Blasting Abrasives
• Effective Date: 01-Jun-2010
• Referred By: ASTM F941-99(2019) - Standard Practice for Inspection of Marine Surface Preparation and Coating Application
• Effective Date: 10-Jan-2003
• Referred By: ASTM D5498-12a(2018) - Standard Guide for Developing a Training Program for Personnel Performing Coating and Lining Work Inspection for Nuclear Facilities
• Effective Date: 10-Jan-2003
• Referred By: ASTM E3355-23 - Standard Guide for Characterization of Coal Combustion Products (CCPs) in Storage Area(s) for Beneficial Use
• Effective Date: 10-Jan-2003
• Referred By: ASTM D7055-19 - Standard Practice for Preparation (by Abrasive Blast Cleaning) of Hot-Rolled Carbon Steel Panels for Testing of Coatings
• Effective Date: 10-Jan-2003
• Referred By: ASTM D7393-16(2020) - Standard Practice for Indicating Oil in Abrasives
• Effective Date: 10-Jan-2003
• Referred By: ASTM D3276-21 - Standard Guide for Painting Inspectors (Metal Substrates)
• Effective Date: 10-Jan-2003

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: D4940 – 98 (Reapproved 2003)
Standard Test Method for
Conductimetric Analysis of Water Soluble Ionic
Contamination of Blasting Abrasives
This standard is issued under the fixed designation D4940; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Summary of Test Method
1.1 This test method describes a procedure for rapid evalu- 3.1 Abrasive and pure water are combined into a slurry that
ation of abrasives for the presence of ionic contamination by is stirred to leach the soluble salts from the abrasive. This
determining the total concentration of water soluble ionic slurry is filtered and conductance of the filtrate is measured.
contaminants by means of a conductivity test. The conductivity, which is related to the concentration of
1.2 This test method does not identify the ionic species soluble ionic materials contaminating the abrasive surface, is
present nor provide quantitative results on each species. calculated from the conductance and the cell constant.
1.3 This test method is based on a volume comparison
4. Significance and Use
among abrasives of similar sizes. A volume comparison is
more closely related to surface area of the abrasives than is a 4.1 By-product abrasives manufactured from slags that are
air cooled or quenched with pure water, normally contain low
weight comparison.
1.4 This standard does not purport to address all of the concentrations of ionic materials, as do mined mineral abra-
sives. However, slags quenched with seawater or other con-
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- taminated water, contain high amounts of ionic material as
does seashore sand. This contamination of the abrasive can
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. transfer to the steel surfaces being blasted, where it may
accelerate corrosion. This test is useful in establishing the
2. Referenced Documents
cleanliness of the abrasive at the jobsite.
2.1 ASTM Standards: 4.2 This test method provides a value that indicates the
D1193 Specification for Reagent Water concentration of total water soluble ions based on their
E832 Specification for Laboratory Filter Papers electrolytic mobility. Thus, it provides an indication of ionic
2.2 Other Standard: corrosion potential.
ISO 11127-6 Preparation of Steel Substrates before Appli-
NOTE 1—A typical value of conductivity for a high level of contami-
cation of Paints and Related Products - Test Methods for
nation is 500 µmho/cm. A typical value for a low level of contamination
Non-Metallic Blast CleaningAbrasives - Part 6: Determi-
is 50µ mho/cm.
nation of Water-Soluble Contaminants by Conductivity
5. Apparatus
Measurement
2.3 SSPC: The Society for Protective Coatings
5.1 Conductivity Bridge and Cell—Any commercial con-
SSPC-AB 1 “Specification for Mineral and SlagAbrasives
ductivity bridge and conductivity cell having a range of at least
5µ mho/cm to 1 000 000 µmho/cm and temperature compen-
sationcapabilityissatisfactory.Eitheradip-type,pipet-type,or
This test method is under the jurisdiction of ASTM Committee D01 on Paint
cup-type cell may be used. A means of adjusting for tempera-
and Related Coatings, Materials, andApplications and is the direct responsibility of
ture or controlling the temperature is essential. While some
Subcommittee D01.46 on Industrial Protective Coatings.
instrumentshaveanadjustmenttocompensatefortemperature,
Current edition approved Jan. 10, 2003. Published March 2003. Originally
approved in 1989. Last previous edition approved in 1998 as D4940 - 98. DOI:
one means is to use a 25°C constant temperature bath.Another
10.1520/D4940-98R03.
method is to stir the solution with a clean thermometer while
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
the vessel is warmed or cooled by an external source.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
NOTE 2—ISO 11127-6 is another method for assessing the level of
the ASTM website.
3 soluble salt contamination present in an abrasive. It differs from this test
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
method in two major areas:
4th Floor, New York, NY 10036, http://www.ansi.org.
(1)The ISO method uses a weight to volume ratio between the abrasive
Available from Society for Protective Coatings (SSPC), 40 24th St., 6th Floor,
Pittsburgh, PA 15222-4656, http://www.sspc.org. and the fluid (deionized water) used to extract soluble salts from the
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4940 – 98 (2003)
abrasive. The ASTM method allows a user to measure a loose packed
lot, batch, day’s pack, or other unit of production in the
volume of abrasive and mix that abrasive with an equal volume of reagent
shipment. When no markings distinguishing between units of
water. The ISO method is well suited to use in a laboratory setting but is
production appear, take samples from the different packages in
poorly suited to use in the field. TheASTM method is well suited for use
the ratio of two samples for each 5000 kg, except that for
in the field or laboratory.
shipments of less than 5000 kg, take two samples. Test the
(2) The ISO method reports the effect of the level of extracted salts in
samples separately.
terms of milliSiemens/m, whereas this test method uses µmho/cm. The
ISO method uses strict SI units, this test method reports using SI
8. Calibration and Standardization
compliant units.
Method to Method Comparison:
8.1 Determination of Cell Constant:
The reader is warned that it is difficult to make direct comparisons
8.1.1 The conductivity cell will come with a predetermined
between the results of these two different methods of analysis.
constant. This constant should be checked periodically, one
Weight/Volume versus Volume/Volume Method Considerations:
method being as follows:
In the ASTM Method the weight of the abrasive is not known; this
8.1.1.1 Prepare a standard solution such as a 0.0005 N
makes it impossible to assess the ratio between conductivity values
determined using this test method procedure and those determined using solution of KCl by diluting a 0.02 N KCl solution with water
the ISO 11127-6 procedure.
or by dissolving 0.0372 g of KCl (weighed after heating for 1
Comparisons Between Reported Units for Each Method:
h at 105°C) in water, followed by dilution to 1 L. Cool and
An independent study by SSPC showed that the relative order of
measure the conductance at 25°C as described in Section 9.
extracted salts using each type of procedure on abrasive materials was
Calculate the cell constant, K , as follows:
identical. The ranked order correlation between the two methods was
unity. There was no direct correlation possible between numerical results
K 5 ~C /C !
25 s m
obtained and reported by the two different methods. Abrasives that
(1)
showed qualifying extrac
...