ASTM C168-00

Standard Terminology Relating to Thermal Insulating Materials

SCOPE
1.1 This standard provides definitions, symbols, units, and abbreviations of terms used in ASTM standards pertaining to thermal insulating materials, and to materials associated with them.

General Information

• Status: Historical
• Publication Date: 09-May-2001
• ICS: 01.040.91 - Construction materials and building (Vocabularies)
• ICS: 91.100.60 - Thermal and sound insulating materials
• Technical Committee: C16 - Thermal Insulation
• Drafting Committee: C16.94 - Terminology

Relations

• Replaced By: ASTM C168-01 - Standard Terminology Relating to Thermal Insulation
• Effective Date: 10-May-2001
• Referred By: ASTM F3340-22 - Standard Test Method for Thermal Resistance of Camping Mattresses Using a Guarded Hot Plate Apparatus
• Effective Date: 10-May-2001
• Referred By: ASTM C1902-22a - Standard Specification for Cellular Glass Insulation Used in Building and Roof Applications
• Effective Date: 10-May-2001
• Referred By: ASTM C1224-22 - Standard Specification for Reflective Insulation for Building Applications
• Effective Date: 10-May-2001
• Referred By: ASTM E2988-17(2022) - Standard Practice for Specimen Preparation and Mounting of Flexible Fibrous Glass Insulation for Metal Buildings to Assess Surface Burning Characteristics
• Effective Date: 10-May-2001
• Referred By: ASTM C534/C534M-23 - Standard Specification for Preformed Flexible Elastomeric Cellular Thermal Insulation in Sheet and Tubular Form
• Effective Date: 10-May-2001
• Referred By: ASTM C516-19 - Standard Specification for Vermiculite Loose Fill Thermal Insulation
• Effective Date: 10-May-2001
• Referred By: ASTM C1919-22 - Standard Practice for Measurement of the Steady-State Thermal Transmission Properties of Small Specimens Using the Heat Flow Meter Apparatus
• Effective Date: 10-May-2001
• Referred By: ASTM C303-21 - Standard Test Method for Dimensions and Density of Preformed Block and Board–Type Thermal Insulation
• Effective Date: 10-May-2001
• Referred By: ASTM C1427-21 - Standard Specification for Extruded Preformed Flexible Cellular Polyolefin Thermal Insulation in Sheet and Tubular Form
• Effective Date: 10-May-2001
• Referred By: ASTM C755-20 - Standard Practice for Selection of Water Vapor Retarders for Thermal Insulation
• Effective Date: 10-May-2001
• Referred By: ASTM C1071-19 - Standard Specification for Fibrous Glass Duct Lining Insulation (Thermal and Sound Absorbing Material)
• Effective Date: 10-May-2001
• Referred By: ASTM C1559-15(2021) - Standard Test Method for Determining Wicking of Fibrous Glass Blanket Insulation (Aircraft Type)
• Effective Date: 10-May-2001
• Referred By: ASTM C488-16(2023) - Standard Test Method for Conducting Exterior Exposure Tests of Finishes for Thermal Insulation
• Effective Date: 10-May-2001
• Referred By: ASTM C1767-21 - Standard Specification for Stainless Steel Jacketing for Insulation
• Effective Date: 10-May-2001

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 168 – 00
Standard Terminology Relating to
1
Thermal Insulation
This standard is issued under the fixed designation C 168; 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 apparent thermal resistivity, r , n—a thermal resistivity
a
assigned to a material that exhibits thermal transmission by
1.1 This standard provides definitions, symbols, units, and
several modes of heat transfer resulting in property variation
abbreviations of terms used in ASTM standards pertaining to
with specimen thickness, or surface emittance. See resistiv-
thermal insulating materials, and to materials associated with
ity, thermal.
them.
DISCUSSION—See entire discussion under apparent thermal conduc-
2. Referenced Documents
tivity.
2.1 ISO Standard:
blackbody, n—the ideal, perfect emitter and absorber of
ISO 7345 Thermal Insulation—Physical Quantities and
thermal radiation. It emits radiant energy at each wavelength
2
Definitions
at the maximum rate possible as a consequence of its
temperature, and absorbs all incident radiance.
3. Terminology
blanket insulation, n—a relatively flat and flexible insulation
3.1 Definitions:
in coherent sheet form furnished in units of substantial area.
absorptance, n—the ratio of the radiant flux absorbed by a
blanket insulation, metal mesh, n— blanket insulation cov-
body to that incident upon it.
ered by flexible metal-mesh facings attached on one or both
absorption, n—transformation of radiant energy to a different
sides.
form of energy by interaction with matter.
block insulation, n—rigid insulation preformed into rectangu-
apparent thermal conductivity, l , k , n—a thermal con-
lar units.
a a
ductivity assigned to a material that exhibits thermal trans-
board insulation, n—semirigid insulation preformed into
mission by several modes of heat transfer resulting in
rectangular units having a degree of suppleness particularly
property variation with specimen thickness, or surface emit-
related to their geometrical dimensions.
tance. See conductivity, thermal.
calcium silicate, n—insulation composed principally of hy-
drous calcium silicate, and which usually contains reinforc-
DISCUSSION—Thermal conductivity and resistivity are normally con-
ing fibers.
sidered to be intrinsic or specific properties of materials and, as such,
cellular elastomeric, n—insulation composed principally of
should be independent of thickness. When nonconductive modes of
heat transfer are present within the specimen (radiation, free convec- natural or synthetic elastomers, or both, processed to form a
tion) this may not be the case. To indicate the possible presence of this
flexible, semirigid, or rigid foam which has a predominantly
phenomena (for example, thickness effect) the modifier “apparent” is
closed-cell structure.
used, as in apparent thermal conductivity.
cellular glass, n—insulation composed of glass processed to
DISCUSSION—Test data using the “apparent” modifier must be quoted
form a rigid foam having a predominantly closed-cell
only for the conditions of the measurement. Values of thermal conduc-
structure.
tance (material C) and thermal resistance (material R) calculated from
apparent thermal conductivity or resistivity, are valid only for the same cellular polystyrene, n—insulation composed principally of
conditions.
polymerized styrene resin processed to form a rigid foam
DISCUSSION—Test data labeled with “apparent” shall not include any
having a predominantly closed-cell structure.
equipment related measurement errors induced due to measurement
cellular polyurethane, n—insulation composed principally of
attempts beyond an apparatus range or calibration.
the catalyzed reaction product of polyisocyanate and poly-
DISCUSSION—Use of the “apparent” modifier with system C or system
hydroxy compounds, processed usually with fluorocarbon
R measurements is not permitted.
gas to form a rigid foam having a predominantly closed-cell
structure.
1
This terminology is under the jurisdiction of ASTM Committee C16 on
cellulosic fiber, n—insulation composed principally of cellu-
Thermal Insulation and is the direct responsibility of Subcommittee C16.94 on
lose fibers usually derived from paper, paperboard stock, or
Terminology.
Current edition approved June 10, 2000. Published September 2000. Originally wood, with or without binders.
published as C 168 – 41 T. Last previous edition C 168 – 97.
cement, finishing, n—a mixture of dry fibrous or powdery
2
Available from American National Standards Institute, 11 W. 42nd St., 13th
materials, or both, that when mixed with water develops a
Floor, New York, NY 10036
...