ASTM E104-02

Standard Practice for Maintaining Constant Relative Humidity by Means of Aqueous Solutions

SIGNIFICANCE AND USE
Standard value relative humidity environments are important for conditioning materials in shelf-life studies or in the testing of mechanical properties such as dimensional stability and strength. Relative humidity is also an important operating variable for the calibration of many species of measuring instruments.
SCOPE
1.1 This practice describes one method for generating constant relative humidity (rh) environments in relatively small containers.
1.2 This practice is applicable for obtaining constant relative humidities ranging from dryness to near saturation at temperatures spanning from 0 to 50—C.
1.3 This practice is applicable for closed systems such as environmental conditioning containers and for the calibration of hygrometers.
1.4 This practice is not recommended for the generation of continuous (flowing) streams of constant humidity unless precautionary criteria are followed to ensure source stability. (See Section 9.)
1.5 Caution-Saturated salt solutions are extremely corrosive, and care should be taken in their preparation and handling. There is also the possibility of corrosive vapors in the atmospheres over the saturated salt solutions.
1.6 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. For more specific safety precautionary information see 1.5 and 10.1.

General Information

• Status: Historical
• Publication Date: 09-Oct-2002
• ICS: 19.040 - Environmental testing
• Technical Committee: D22 - Air Quality
• Drafting Committee: D22.11 - Meteorology

Relations

• Replaces: ASTM E104-85(1996) - Standard Practice for Maintaining Constant Relative Humidity by Means of Aqueous Solutions
• Effective Date: 10-Oct-2002
• Replaced By: ASTM E104-02(2007) - Standard Practice for Maintaining Constant Relative Humidity by Means of Aqueous Solutions
• Effective Date: 01-Oct-2007
• Referred By: ASTM D2803-09(2020) - Standard Guide for Testing Filiform Corrosion Resistance of Organic Coatings on Metal
• Effective Date: 10-Oct-2002
• Referred By: ASTM D5032-19 - Standard Practice for Maintaining Constant Relative Humidity by Means of Aqueous Glycerin Solutions
• Effective Date: 10-Oct-2002
• Referred By: ASTM D8365-20 - Standard Test Method for Corrosion of Metal Produced by Contact with Leather
• Effective Date: 10-Oct-2002
• Referred By: ASTM D6329-98(2023) - Standard Guide for Developing Methodology for Evaluating the Ability of Indoor Materials to Support Microbial Growth Using Static Environmental Chambers
• Effective Date: 10-Oct-2002
• Referred By: ASTM D257-14(2021)e1 - Standard Test Methods for DC Resistance or Conductance of Insulating Materials
• Effective Date: 10-Oct-2002
• Referred By: ASTM D3983-98(2019) - Standard Test Method for Measuring Strength and Shear Modulus of Nonrigid Adhesives by the Thick-Adherend Tensile-Lap Specimen
• Effective Date: 10-Oct-2002
• Referred By: ASTM D4000-23 - Standard Classification System for Specifying Plastic Materials
• Effective Date: 10-Oct-2002
• Referred By: ASTM D618-21 - Standard Practice for Conditioning Plastics for Testing
• Effective Date: 10-Oct-2002
• Referred By: ASTM D115-17 - Standard Test Methods for Testing Solvent Containing Varnishes Used for Electrical Insulation
• Effective Date: 10-Oct-2002
• Referred By: ASTM D1779-98(2017) - Standard Specification for Adhesive for Acoustical Materials
• Effective Date: 10-Oct-2002
• Referred By: ASTM F2170-19a - Standard Test Method for Determining Relative Humidity in Concrete Floor Slabs Using in situ Probes
• Effective Date: 10-Oct-2002
• Referred By: ASTM D1653-13(2021) - Standard Test Methods for Water Vapor Transmission of Organic Coating Films
• Effective Date: 10-Oct-2002
• Referred By: ASTM D876-21 - Standard Test Methods for Nonrigid Vinyl Chloride Polymer Tubing Used for Electrical Insulation
• Effective Date: 10-Oct-2002

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:E104–02
Standard Practice for
Maintaining Constant Relative Humidity by Means of
1
Aqueous Solutions
This standard is issued under the fixed designation E 104; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 2.2 Other Document:
DIN50008 “Konstantklimate uber waesserigen Loseungen”
1.1 This practice describes one method for generating con-
(Constant Climates Over Aqueous Solutions).
stant relative humidity (rh) environments in relatively small
4
Part 1: Saturated Salt and Glycerol Solutions.
containers.
1.2 This practice is applicable for obtaining constant rela-
3. Terminology
tive humidities ranging from dryness to near saturation at
3.1 non-hygroscopic material—material which neither ab-
temperatures spanning from 0 to 50°C.
sorbs nor retains water vapor.
1.3 This practice is applicable for closed systems such as
3.2 For definitions of other terms used in this practice refer
environmental conditioning containers and for the calibration
to Terminology D 1356.
of hygrometers.
1.4 This practice is not recommended for the generation of
4. Summary of Practice
continuous (flowing) streams of constant humidity unless
4.1 Standard value relative humidity environments are gen-
precautionary criteria are followed to ensure source stability.
erated using selected aqueous saturated salt solutions.
(See Section 9.)
1.5 Caution—Saturated salt solutions are extremely corro-
5. Significance and Use
sive, and care should be taken in their preparation and
5.1 Standard value relative humidity environments are im-
handling.Thereisalsothepossibilityofcorrosivevaporsinthe
2 portant for conditioning materials in shelf-life studies or in the
atmospheres over the saturated salt solutions.
testing of mechanical properties such as dimensional stability
1.6 This standard does not purport to address all of the
and strength. Relative humidity is also an important operating
safety concerns, if any, associated with its use. It is the
variable for the calibration of many species of measuring
responsibility of the user of this standard to establish appro-
instruments.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. For more specific
6. Interferences
safety precautionary information see 1.5 and 10.1.
6.1 Temperature regulation of any solution-head space en-
vironment to 60.1°C is essential for realizing generated
2. Referenced Documents
relative humidity values within 60.5 % (expected).
3
2.1 ASTM Standards:
6.2 Some aqueous saturated salt solutions change composi-
D 1193 Specification for Reagent Water
tion following preparation by hydrolysis or by reaction with
D 1356 Terminology Relating to Sampling and Analysis of
environmental components (for example, carbon dioxide ab-
Atmospheres
sorption by alkaline materials). These solutions should be
freshly prepared on each occasion of use.
1
This practice is under the jurisdiction ofASTM Committee D22 onAir Quality
and is the direct responsibility of Subcommittee D22.11 on Meteorology.
7. Apparatus
Current edition approved October 10, 2002. Published December 2002. Origi-
7.1 Container—The container, including a cover or lid
nally published as E 104 – 51. Last previous edition E 104 – 85(96).
2
Opila, R., Jr., Weschler, C. J., and Schubert, R., “Acidic Vapors Above which can be secured airtight, should be made of corrosion
Saturated Salt Solutions Commonly Used for Control of Humidity,” IEEE Trans.
resistant, non-hygroscopic material such as glass. A metal or
Components, Hybrids and Manufacturing Technology, Vol 12, No. 1, March 1989,
pp. 114–120.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Published by Deutsches Institut für Normung, 4-10 Burggrzfenstrasse Postfach
Standards volume information, refer to the standard’s Document Summary page on 1107, D-1000 Berlin, Federal Republic of Germany. Also available from ANSI
the ASTM website. Publication Office, New York, NY.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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E104–02
TABLE 1 Humidity Fixed Point (HFP) Salt Solutions
HFP Designation Salt Name Chemical Symbol Temperature Range (°C)
HFP 4 Caesium fluoride CsF 15 to 80
HFP 7 Lithium bromide LiBr 5 to 80
HFP 12 Lithium chloride LiCl 5 to 80
HFP 23 Potassium acetate CH COOK 10 to 30
3
HFP 33 Magnes
...