ASTM E715-80(2022)

Standard Specification for Gravity-Convection and Forced-Circulation Water Baths

ABSTRACT
This specification covers the performance requirements for four types (Types IA, IB, IIA, and IIB) of unloaded and covered general-purpose gravity-convection and forced-circulation water baths ordinarily used in testing operations. The temperature within the bath chamber shall be controllable by an automatic device and, when examined by appropriate test methods, shall be uniform within the tolerances as to uniformity and time constant specified for the particular type of bath.
SCOPE
1.1 This specification covers the performance requirements for general-purpose water baths ordinarily used in testing operations. It is applicable to gravity-convection and forced-circulation water baths operating in the range from 5 °C above ambient to 100 °C and having a water volume up to 100 L.  
1.2 This specification covers unloaded, covered water baths.  
1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Dec-2021
• ICS: 71.040.20 - Laboratory ware and related apparatus
• Technical Committee: E41 - Laboratory Apparatus
• Drafting Committee: E41.06 - Laboratory Instruments and Equipment

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:E715 −80 (Reapproved 2022)
Standard Specification for
1
Gravity-Convection and Forced-Circulation Water Baths
This standard is issued under the fixed designation E715; 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 3.2 The “time constant” is an arbitrary measure of the rate at
which a standard specimen is heated following the procedure
1.1 This specification covers the performance requirements
of 4.2. The value of the time constant shall not exceed the
for general-purpose water baths ordinarily used in testing
maximum value given in Table 1 for the particular type of bath.
operations. It is applicable to gravity-convection and forced-
circulation water baths operating in the range from 5 °C above
4. Test Methods
ambient to 100 °C and having a water volume up to 100 L.
4.1 Temperature Uniformity:
1.2 This specification covers unloaded, covered water baths.
4.1.1 Place five calibrated temperature sensors in the un-
1.3 This international standard was developed in accor-
loaded water bath with diffuser plate in place and at lowest
dance with internationally recognized principles on standard-
position and water level approximately 38 mm (1.5 in.) from
ization established in the Decision on Principles for the
the top. Temperature sensors may be platinum resistance
Development of International Standards, Guides and Recom-
elements or thermistors having a time constant of 2.5 s or less,
mendations issued by the World Trade Organization Technical
or thermocouples made of iron or copper-constantan wire
Barriers to Trade (TBT) Committee.
approximately 0.5 mm (24-gauge) in diameter and having a
junction size not larger than 2 mm (0.08 in.). Locate one sensor
2. Classification
in each of the four corners of the bath approximately 50 mm (2
2.1 This specification covers the following four types of
in.) from each wall and midway between the diffuser plate and
water baths:
the water surface. Locate the fifth sensor within 25 mm (1 in.)
2.1.1 Type IA—A gravity-convection bath having a unifor-
of the geometric center of the bath. Cover the bath either with
mity of temperature not greater than 62 % of the differential
the standard cover used with the bath or a flat sheet of stainless
between ambient and operating temperature.
steel. If necessary, holes may be made in the cover, in the
2.1.2 Type IB—A gravity-convection bath having a unifor-
proper locations to accommodate the sensors. Rubber stoppers
mity of temperature not greater than 64 % of the differential
shall be used to plug the holes in order to minimize vapor loss.
between ambient and operating temperature.
2.1.3 Type IIA—A forced-circulation bath having a unifor- NOTE 2—If calibrated thermocouples are not available, five thermo-
couples made from the same spool of wire may be used, provided they
mity of temperature not greater than 61 % of the differential
give the same value for temperature when placed adjacent to one another
between ambient and operating temperature.
in the bath at test temperature.
2.1.4 Type IIB—A forced-circulation bath having a unifor-
4.1.2 Bring the bath to the desired temperature and allow it
mity of temperature not greater than 62 % of the differential
to reach a steady state. Record the temperatures of the five
between ambient and operating temperature.
sensors for a period of 3 h. Determine from the record the
NOTE 1—Uncovered water baths will generally have uniformities
maximum deviation in both plus and minus direction from the
broader by an additional 0.1 °C.
desired temperature. Ambient temperature shall not vary by
3. Performance Requirements more than a total of 4 °C and the line voltage shall not vary by
more than a total of 5 % during the test.
3.1 The temperature within the bath chamber shall be
controllable by an automatic device and shall be uniform
4.2 Time Constant:
within the tolerances given in Table 1 for the particular type of
4.2.1 Heat the bath to 60 °C and allow it to stabilize for 1 h.
bath when tested in accordance with 4.1.
Prepare a differential thermocouple using 24-gauge iron-
constantan thermocouple wire. There should be approximately
1
1 m (39 in.) between junctions.
This specification is under the jurisdiction of ASTM Committee E41 on
Laboratory Apparatus and is the direct responsibility of Subcommittee E41.06 on
4.2.2 Fill two 500-mL Erlenmeyer flasks with water. Place
Laboratory Instruments and Equipment.
one junction of the differen
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