ASTM C870-96

Standard Practice for Conditioning of Thermal Insulating Materials

SCOPE
1.1 This practice covers the conditioning of thermal insulating materials for tests. Since prior exposure of insulating materials to high or low humidity may affect the equilibrium moisture content, a procedure is also given for preconditioning the materials.  
1.2  This standard does not purport to address all of the safety problems, 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: 31-Dec-1999
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.31 - Chemical and Physical Properties

Relations

• Replaced By: ASTM C870-96(2000) - Standard Practice for Conditioning of Thermal Insulating Materials
• Effective Date: 01-Jan-2000
• Referred By: ASTM C1512-10(2020) - Standard Test Method for Characterizing the Effect of Exposure to Environmental Cycling on Thermal Performance of Insulation Products
• Effective Date: 01-Jan-2000
• Referred By: ASTM C302-13(2022) - Standard Test Method for Density and Dimensions of Preformed Pipe-Covering-Type Thermal Insulation
• Effective Date: 01-Jan-2000
• Referred By: ASTM C1363-19 - Standard Test Method for Thermal Performance of Building Materials and Envelope Assemblies by Means of a Hot Box Apparatus
• Effective Date: 01-Jan-2000
• Referred By: ASTM C335/C335M-23 - Standard Test Method for Steady-State Heat Transfer Properties of Pipe Insulation
• Effective Date: 01-Jan-2000
• Referred By: ASTM C533-17(2023) - Standard Specification for Calcium Silicate Block and Pipe Thermal Insulation
• Effective Date: 01-Jan-2000
• Referred By: ASTM C578-22 - Standard Specification for Rigid, Cellular Polystyrene Thermal Insulation
• Effective Date: 01-Jan-2000
• Referred By: ASTM C1774-13(2019) - Standard Guide for Thermal Performance Testing of Cryogenic Insulation Systems
• Effective Date: 01-Jan-2000
• Referred By: ASTM C209-20 - Standard Test Methods for Cellulosic Fiber Insulating Board
• Effective Date: 01-Jan-2000
• Referred By: ASTM C303-21 - Standard Test Method for Dimensions and Density of Preformed Block and Board–Type Thermal Insulation
• Effective Date: 01-Jan-2000
• Referred By: ASTM C1763-20 - Standard Test Method for Water Absorption by Immersion of Thermal Insulation Materials
• Effective Date: 01-Jan-2000
• Referred By: ASTM C764-19 - Standard Specification for Mineral Fiber Loose-Fill Thermal Insulation
• Effective Date: 01-Jan-2000
• Referred By: ASTM C203-22 - Standard Test Methods for Breaking Load and Flexural Properties of Block-Type Thermal Insulation
• Effective Date: 01-Jan-2000

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: C 870 – 96
Standard Practice for
Conditioning of Thermal Insulating Materials
This standard is issued under the fixed designation C 870; 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 3.1.1.1 Discussion—This is variously referred to as mois-
ture content, or moisture “as is” or “as received.”
1.1 This practice covers the conditioning of thermal insu-
3.1.1.2 Discussion—This is also referred to as moisture
lating materials for tests. Since prior exposure of insulating
regain (frequently contracted to “regain”), or moisture content
materials to high or low humidity may affect the equilibrium
on the “oven-dry,” “moisture-free,” or “dry” basis.
moisture content, a procedure is also given for preconditioning
3.1.2 moisture equilibrium—the condition reached by a
the materials.
sample when the net difference between the amount of mois-
1.2 This standard does not purport to address all of the
ture sorbed and the amount desorbed, as shown by a change in
safety concerns, if any, associated with its use. It is the
mass, shows no trend and becomes insignificant.
responsibility of the user of this standard to establish appro-
3.1.2.1 Discussion—Superficial equilibrium with the film of
priate safety and health practices and determine the applica-
air in contact with the specimen is reached very rapidly. Stable
bility of regulatory limitations prior to use.
equilibrium can be reached in a reasonable time only if the air
2. Referenced Documents
to which the sample is exposed is in motion. Stable equilibrium
with air in motion is considered to be realized when successive
2.1 ASTM Standards:
weighings do not show a progressive change in mass greater
C 168 Terminology Relating to Thermal Insulating Materi-
than the tolerances established for the various insulating
als
materials.
E 41 Terminology Relating to Conditioning
3.1.3 moisture regain—the moisture in a material deter-
E 171 Specification for Standard Atmospheres for Condi-
mined under prescribed conditions, and expressed as a percent-
tioning and Testing Flexible Barrier Materials
age of the mass of the moisture-free specimen.
E 337 Test Method for Measuring Humidity with a Psy-
3.1.3.1 Discussion—Moisture regain calculations are com-
chrometer (the Measurement of Wet- and Dry-Bulb Tem-
monly based on the mass of a specimen that has been dried by
peratures)
heating in an oven. If the air in the oven contains moisture, the
2.2 ISO Standard:
oven-dried specimen will contain some moisture even when it
ISO 544 Standard Atmospheres for Conditioning and/or
no longer shows a significant change in mass. In order to
Testing
ensure that the specimen is moisture-free, it must be exposed to
3. Terminology
desiccated air until it shows no further significant change in its
mass. For drying temperatures above 100°C (212°F), the
3.1 Definitions—Definitions of terms in the field of thermal
moisture content of the oven atmosphere is negligible.
insulating materials are given in Terminology C 168. The
3.1.3.2 Discussion—Moisture regain may be calculated
following definitions are derived from Terminology E 41:
from moisture content using Eq 1, and moisture content may be
3.1.1 moisture content—the moisture present in a material,
calculated from moisture regain using Eq 2 as follows:
as determined by definite prescribed methods, expressed as a
percentage of the mass of the sample on either of the following
C
R 5 3 100 (1)
bases: (1) original mass (see 3.1.1); (2) moisture-free weight 100 2 C
(see 3.1.2).
R
C 5 3 100 (2)
100 1 R
This practice is under the jurisdiction of ASTM Committee C-16 on Thermal where:
Insulation and is the direct responsibility of Subcommittee C16.31 on Chemical and
C 5 moisture content, % (see 3.1.1), and
Physical Properties.
R 5 moisture regain, % (see 3.1.3).
Current edition approved Dec. 10, 1996. Published February 1997. Originally
3.2 Definitions of Terms Specific to This Standard—The
published as C 870 – 77. Last previous edition C 870 – 77.
Annual Book of ASTM Standards, Vol 04.06. following descriptions apply only to the usage of terms in this
Annual Book of ASTM Standards, Vol 14.02.
practice:
Annual Book of ASTM Standards, Vol 15.09.
3.2.1 conditioned moisture equilibrium—The moisture con-
Annual Book of ASTM Standards, Vol 11.03.
dition reached by a sample or specimen during free exposure to
Available from American National Standards Institute, 11 West 42nd Street,
13th Floor, New York, NY 10036. moving air controlled at specified conditions. For test purposes,
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
C 870
NOTE 1—In some cases (for example, dimensionally unstable materi-
moisture equilibrium must be reached by absorption, starting
als), the dry mass cannot easily be established and original mass has to be
from a relatively low moisture content (see 3.2.4). Moisture
used.
equilibrium for testing is considered to have been reached
5.2 It may be important to the user of thermal insulation to
when the rate of increase in the mass of a sample or specimen
does not exceed that specified for the material being tested. In know physical properties (influenced by humidity) at the
ambient conditions of use, as well as at standard conditions
the absence of a specified rate, an increase of less than 0.1 %
of the sample mass after a 24-h exposure is considered customarily specified for testing. In such instances, those
special ambient conditions should be stated in the pertinent
satisfactory.
3.2.2 preconditioned moisture equilibrium—The moisture material specifications and test methods.
condition reached by a sample or specimen after exposure to
6. Apparatus
moving air at the standard atmosphere for preconditioning. The
6.1 Conditioning Room or Chamber:
final condition may be established after a specified period of
6.1.1 Equipment for maintaining the standard atmosphere
time, or at a moisture equilibrium that is considered to have
for testing insulating materials throughout the room or chamber
been reached when the change in mass of a specimen in
within the tolerance given in 3.2.4, and including facilities for
successive weighings made at intervals of not less than 2 h
circulating the air over the exposed sample or specimen or,
does not exceed 0.2 % of the mass of the specimen.
alternatively, facilities such as a revolving rack for moving the
3.2.2.1 Discussion—Because the standard preconditioning
specimens in the prevailing atmosphere.
atmosphere covers a range of relative humidities, the close
6.1.2 Equipment for recording the temperature and relative
approach to equilibrium is, in general, warranted only at the top
of the range. At lower humidities exposure for several hours is humidity of the air in the conditioning room or chamber.
6.2 Instrumentation, for checking the recorded relative hu-
usually sufficient.
3.2.3 standard conditioning atmosphere—Air maintained at midity, as directed on Test Method E 337.
6.3 Preconditioning Cabinet, Room, or Chamber, equipped
a relative humidity of 50 6 5 % and
...