ASTM E145-94(2011)

Standard Specification for Gravity-Convection and Forced-Ventilation Ovens

ABSTRACT
This specification covers the performance requirements for four types (Types IA, IB, IIA, and IIB) of general-purpose air ovens of the gravity-convection and forced-ventilation types ordinarily used in testing operations. The temperature within the testing chamber shall be controllable by an automatic device and, when examined with appropriate test methods provided herein, shall be uniform within the tolerances for temperature uniformity, time constant, and rate of ventilation requirements for the particular type of oven.
SCOPE
1.1 This specification covers the performance requirements for general-purpose air ovens ordinarily used in testing operations, which have a testing chamber up to 0.6 m3  (25 ft3) in volume. It is applicable to gravity-convection ovens designed to operate over all or part of the temperature range from 20°C above ambient temperature to 200°C and to forced-ventilation ovens designed to operate over all or part of the temperature range from 20°C above ambient temperature to 500°C.
Note 1—Ovens are designed for maximum operating temperatures of about 200°C, 300°C, and 500°C, the thermal insulation and cost of the oven being dependent on the maximum temperature required.
1.2 This specification does not include safety requirements that are essential for ovens used in the presence of combustible vapors or gases.
1.3 The values stated in inch-pound units are to be regarded as the standard. The metric equivalents of inch-pound units may be approximate.

General Information

• Status: Historical
• Publication Date: 30-Nov-2011
• ICS: 71.040.10 - Chemical laboratories. Laboratory equipment
• Technical Committee: E41 - Laboratory Apparatus
• Drafting Committee: E41.06 - Laboratory Instruments and Equipment

Relations

• Replaces: ASTM E145-94(2006) - Standard Specification for Gravity-Convection And Forced-Ventilation Ovens
• Effective Date: 01-Dec-2011
• Replaced By: ASTM E145-19 - Standard Specification for Gravity-Convection and Forced-Ventilation Ovens
• Effective Date: 01-Mar-2019
• Referred By: ASTM D7444-18a - Standard Practice for Heat and Humidity Aging of Oxidatively Degradable Plastics
• Effective Date: 01-Dec-2011
• Referred By: ASTM D1754/D1754M-20 - Standard Test Method for Effects of Heat and Air on Asphaltic Materials (Thin-Film Oven Test)
• Effective Date: 01-Dec-2011
• Referred By: ASTM D5095-91(2022) - Standard Test Method for Determination of the Nonvolatile Content in Silanes, Siloxanes and Silane-Siloxane Blends Used in Masonry Water Repellent Treatments
• Effective Date: 01-Dec-2011
• Referred By: ASTM D2168-10(2018) - Standard Practices for Calibration of Laboratory Mechanical-Rammer Soil Compactors
• Effective Date: 01-Dec-2011
• Referred By: ASTM D350-21 - Standard Test Methods for Flexible Treated Sleeving Used for Electrical Insulation
• Effective Date: 01-Dec-2011
• Referred By: ASTM D2684/D2684M-15 - Standard Test Method for Permeability of Thermoplastic Containers to Packaged Reagents or Proprietary Products (Withdrawn 2024)
• Effective Date: 01-Dec-2011
• Referred By: ASTM D1934-20 - Standard Test Method for Oxidative Aging of Electrical Insulating Liquids by Open-Beaker Method
• Effective Date: 01-Dec-2011
• Referred By: ASTM D2067-97(2020) - Standard Test Method for Coarse Particles in Printing Ink Dispersions
• Effective Date: 01-Dec-2011
• Referred By: ASTM D6150-16 - Standard Test Method for Estimating Processing Losses of Plastisols and Organosols Due to Volatility
• Effective Date: 01-Dec-2011
• Referred By: ASTM D6419-00(2023) - Standard Test Method for Volatile Content of Sheet-Fed and Coldset Web Offset Printing Inks
• Effective Date: 01-Dec-2011
• Referred By: ASTM C120/C120M-19 - Standard Test Methods for Flexure Testing of Structural and Roofing Slate
• Effective Date: 01-Dec-2011
• Referred By: ASTM D1140-17 - Standard Test Methods for Determining the Amount of Material Finer than 75-μm (No. 200) Sieve in Soils by Washing
• Effective Date: 01-Dec-2011
• Referred By: ASTM D6766-20a - Standard Test Method for Evaluation of Hydraulic Properties of Geosynthetic Clay Liners Permeated with Potentially Incompatible Aqueous Solutions
• Effective Date: 01-Dec-2011

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:E145 −94 (Reapproved 2011)
Standard Specification for
Gravity-Convection and Forced-Ventilation Ovens
This standard is issued under the fixed designation E145; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 3. Performance Requirements
1.1 This specification covers the performance requirements
3.1 The temperature within the testing chamber shall be
for general-purpose air ovens ordinarily used in testing
controllable by an automatic device, and shall be uniform
3 3
operations, which have a testing chamber up to 0.6 m (25 ft )
within the tolerances given in Table 1 for the particular type of
in volume. It is applicable to gravity-convection ovens de-
oven when tested in accordance with Section 4.
signed to operate over all or part of the temperature range from
3.2 The“timeconstant”isanarbitrarymeasureoftherateat
20°C above ambient temperature to 200°C and to forced-
which a standard specimen is heated following the procedure
ventilation ovens designed to operate over all or part of the
prescribedinSection5.Thevalueofthetimeconstantshallnot
temperature range from 20°C above ambient temperature to
exceed the maximum value given in Table 1 for the particular
500°C.
type of oven.
NOTE 1—Ovens are designed for maximum operating temperatures of
3.3 The rate of ventilation of the testing chamber shall
about 200°C, 300°C, and 500°C, the thermal insulation and cost of the
oven being dependent on the maximum temperature required. conform to the requirements specified in Table 1 for the
particular type of oven when measured in accordance with the
1.2 This specification does not include safety requirements
procedure given in Section 6.
that are essential for ovens used in the presence of combustible
vapors or gases.
TEST METHODS
1.3 The values stated in inch-pound units are to be regarded
as the standard. The metric equivalents of inch-pound units
4. Temperature Uniformity
may be approximate.
4.1 Placeninecalibratedthermocouples(Note2)madefrom
iron or copper-constantan wire, approximately 0.5 mm in
2. Types
diameter (No. 24 gauge) and having a junction size of not more
2.1 This specification covers the following four types of air
than 2 mm (0.08 in.), in the empty testing chamber with
ovens:
shelves in place and vents open. Locate one thermocouple in
2.1.1 Type IA—An oven ventilated by gravity convection
eachoftheeightcornersoftheovenapproximately5cm(2in.)
having a uniformity of temperature within 62 % of the
from each wall and place the ninth thermocouple within 2.5 cm
differential between oven and ambient temperatures.
(1 in.) of the geometric center of the chamber. A minimum
2.1.2 Type IB—An oven ventilated by gravity convection
length of 30 cm (12 in.) of lead wire for each thermocouple
having a uniformity of temperature within 65 % of the
shall be inside the oven to minimize the conduction of heat
differential between oven and ambient temperatures.
from the thermocouple.
2.1.3 Type IIA—An oven having forced ventilation and a
NOTE 2—If calibrated thermocouples are not available, nine thermo-
uniformity of temperature within 61 % of the differential
couplesmadefromthesamespoolofwiremaybeusedprovidedtheygive
between oven and ambient temperatures.
the same value for temperature when placed adjacent to one another in the
2.1.4 Type IIB—An oven having forced ventilation and a
testing chamber at the temperature of test.
uniformity of temperature within 62.5 % of the differential
4.2 Bring the oven to the specified temperature and allow it
between oven and ambient temperatures.
to reach a steady state (Note 3). Record the temperatures of the
nine thermocouples for a period of at least 24 h, and determine
from the record the maximum deviation of each point from the
This specification is under the jurisdiction of ASTM Committee E41 on
Laboratory Apparatus and is the direct responsibility of Subcommittee
desiredtemperatures.Theambientroomtemperatureshallvary
E41.06Weighing Devices.
by not more than a total of 10°C, and the line voltage for
Current edition approved Dec. 1, 2011. Published December 2011. Originally
electrically heated ovens shall vary by not more than a total of
approved in 1959. Last previous edition approved in 2006 as E145 – 94 (2006).
DOI: 10.1520/E0145-94R11. 5 % during the test.
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E145−94 (2011)
TABLE 1 Performance Requirements for Ovens
Characteristic Type IA Type IB Type IIA Type IIB
Deviation from specified temperature of test throughout testing chamber during
24-h period for the following differentials
...