ASTM D7358-07(2013)
(Test Method)Standard Test Method for Water Content of Paints by Quantitative Calcium Hydride Reaction Test Kit
Standard Test Method for Water Content of Paints by Quantitative Calcium Hydride Reaction Test Kit
SIGNIFICANCE AND USE
4.1 Although Test Method D4017 is widely used for the determination of water in paints and related materials, this method may overcome some of the variability found in the Karl Fischer method.
4.2 Control of water content is often important in controlling the performance of paints, and it is critical in determining volatile organic compound (VOC) content when VOC content is measured by difference from total volatile matter and water content as required in certain federal and state regulations.
SCOPE
1.1 This test method describes the determination of the total water content of paints using a calcium hydride reaction test kit, or water content between 2 and 85 % water.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D7358 − 07 (Reapproved 2013)
Standard Test Method for
Water Content of Paints by Quantitative Calcium Hydride
Reaction Test Kit
This standard is issued under the fixed designation D7358; 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 water in the reacted sample extract. The actual weight percent
water in the whole paint sample is manually calculated using
1.1 This test method describes the determination of the total
the exact weights of the paint sample and the diluted extract
water content of paints using a calcium hydride reaction test
sample, if used.
kit, or water content between 2 and 85 % water.
1.2 The values stated in SI units are to be regarded as 4. Significance and Use
standard. No other units of measurement are included in this
4.1 Although Test Method D4017 is widely used for the
standard.
determination of water in paints and related materials, this
1.3 This standard does not purport to address all of the
method may overcome some of the variability found in the
safety concerns, if any, associated with its use. It is the
Karl Fischer method.
responsibility of the user of this standard to establish appro-
4.2 Control of water content is often important in control-
priate safety and health practices and determine the applica-
ling the performance of paints, and it is critical in determining
bility of regulatory limitations prior to use.
volatile organic compound (VOC) content when VOC content
is measured by difference from total volatile matter and water
2. Referenced Documents
content as required in certain federal and state regulations.
2.1 ASTM Standards:
D1193 Specification for Reagent Water
5. Interferences
D3925 Practice for Sampling Liquid Paints and Related
5.1 The following compounds, tested at twice the sample
Pigmented Coatings
size,havebeenfoundtoproducenomeasurableresponsetothe
D4017 Test Method for Water in Paints and Paint Materials
calcium hydride reaction test kit and, therefore, cause no
by Karl Fischer Method
interference at levels up to 40 %:
E29 Practice for Using Significant Digits in Test Data to
Ethanol
Determine Conformance with Specifications
Methanol
A
Acetone
3. Summary of Test Method
Methyl Ethyl Ketone
Tetrahydrofuran
3.1 A0.25 mLsample is reacted with a specially formulated
Diethylene Glycol Dimethyl Ether
A
calcium hydride reagent to convert water in the sample to
Ethylene Glycol
Diethylene Glycol
hydrogen gas. The reaction is carried out in a sealed pressure
Dipropylene Glycol
vessel and the resulting pressure is then measured using a
Stearic Acid
specially designed meter programmed to convert gas pressure
2–Ethyl Hexanoic Acid
Lead Oxide (II and III)
into water content. The results are displayed in milligrams of
Aluminum Oxide (Brockman I)
A
0.25 mL sample size program A and B.
This test method is under the jurisdiction of ASTM Committee D01 on Paint
5.2 When using the 5 mL sample size programs, that is,
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials. programs C, D, or E, ethylene glycol and acids have been
Current edition approved June 1, 2013. Published June 2013. Originally
found to produce a positive result in the presence of a small
approved in 2007. Last previous edition approved in 2007 as D7358 – 07. DOI:
amount of water. Ethylene glycol responds at approximately
10.1520/D7358-07R13.
7 % of the volumetric equivalent.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volumeinformation,refertothestandard’sDocumentSummarypageon
the ASTM website. HydroSCOUT User’s Manual.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7358 − 07 (2013)
6. Apparatus 9. Sampling, Test Specimens, and Test Units
6.1 HydroSCOUT System—A test kit system consisting of 9.1 Sample Collection—Take a representative sample of the
theHydroSCOUTmeter,reactiontubes,samplingsyringesand liquid coatings in accordance with Practice D3925. Mix
dilution vials. The entire analytical sequence, including thoroughly before taking specimens for individual tests.
sampling, sample dilution, chemical reactions and
10. Preparation
quantification, is available in kit form using pre-dispensed and
encapsulated reagents. An analytical balance is required in
10.1 Preparation—Remove a sampling syringe with cap
order to obtain the most precise results. In addition, a mechani- and a test tube from the kit box. Check the contents to ensure
cal shaker may be necessary to obtain a representative sample.
that all items are present and intact. If a dilution is to be used,
remove a dilution vial and an additional sampling syringe and
7. Reagents and Materials
cap. Remove the screw cap and rubber septum from the tube
and the cap from the dilution vial, if used. Insert one green
7.1 Purity of Reagents—Reagent grade chemicals shall be
water ampule into the top of the polypropylene ampule sleeve
usedinalltests.Allreagentsshallconformtothespecifications
and replace the holder in the tube.
of the Committee on Analytical reagents of the American
Chemical Society, where such specifications are available.
11. Calibration and Standardization
7.2 Purity of Water—Unless otherwise indicated, reference
11.1 The commercially available meter is calibrated at the
to water shall mean reagent water conforming to Specification
factory over the pressure range of 0 to 60 psig. Each time the
D1193, Type II.
meter is turned on, the pressure transducer recalibrates the 0
7.3 Calcium Hydride (20 %) in HI SOL 10—contained in a
psig point. If this changes significantly from the factory set
crushable glass ampule.
point, an error message will be displayed. This error will also
appear if a tube is accidentally inserted into the meter before
7.4 Water—contained in a crushable glass ampule.
the meter is turned on.
7.5 Diethylene Glycol Dimethyl Ether (Diglyme)—2.25 mL
contained in a glass vial.
12. Procedure
12.1 Sample Introduction for Expected Water Content Less
8. Hazards
Than 15 % (No Dilution)—Work the plunger on an empty
8.1 Store ampules in a cool, dry place. Keep away from
sampling syringe a few times to ensure that it slides easily.
heat, sparks, water and open flames.
Place the tip of the syringe into the paint sample to be tested
8.2 See manufacturer’s instructions and Material Safety
andslowlypullbackontheplungeruntilitreachesthestopand
Data Sheet (MSDS) before use.
cannot be pulled further. Remove the syringe from the paint
sample and wipe any excess paint from the outside of the
8.3 The gray ampule in the tube contains calcium hydride,
syringe with a tissue wipe provided with the kit. Cap the
which is a flammable solid and water reactive.
syringe with the cap provided and weigh; record the weight
8.4 Perform test only in a well ventilated area.
(gross sample weight) to the nearest 0.1 mg. Dispense the
8.5 Always wear rubber gloves and safety glasses.
sample into the reaction tube. Recap the syringe without
wiping,reweighit,andrecordthisweight(sampletareweight).
8.6 Take care to ensure that fingers are not cut by glass in
The difference in the two weights becomes the sample weight
the kits. Each ampule should be crushed only once to reduce
(S ) to be used in Eq 1. Replace the rubber septum (hole on
the risk of glass pieces piercing the sides of the tube.
top) by gripping the tube firmly and pressing the septum down
8.7 When venting reaction tube after completion of test,
with the thumb. (NOTE: Do not squeeze the sides of the tube
point tube upright and away from user and bystander.
while inserting the septum.) Replace the screw cap tightly,
8.8 When breaking the green water ampule after completion turning it until it cannot be turned further. Proceed to step 12.3.
of test, the tube must be shaken vigorously for the full 15
12.2 Sample Introduction for Expected Water Content
seconds to ensure that the water contacting the remaining
Greater Than 15 % (With Dilution)—Work the plunger on an
calcium hydride does not overheat the side of the tube,
empty sampling syringe a few times to ensure that it slides
otherwise tube failure can result.
easily. Place the tip of the syringe into the paint sample to be
tested and slowly pull back on the plunger until it reaches the
stop and cannot be pulled further. Remove the syringe from the
HydroSCOUT is a trademark of the Dexsil Corporation.
5 paint sample and wipe any excess paint from the outside of the
The sole source of supply of this kit known to the committee at this time is
Dexsil Corporation, One Hamden Park Drive, Hamden, CT06517. If you are aware
syringe with a tissue wipe provided with the kit. Cap the
of alternative suppliers, please provide this information to ASTM International
syringe with the cap provided and weigh; record the weight
Headquarters.Your comments will receive careful consideration at a meeting of the
1 (gross sample weight) to the nearest 0.1 mg. Dispense the
responsible technical committee, which you may attend.
sample into the dilution vial containing a premeasured amount
Reagent Chemicals, American Chemical Society Specifications, Am
...
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