ASTM E191-64(2017)

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: E191 −64 (Reapproved 2017)
Standard Specification for
Apparatus For Microdetermination of Carbon and
Hydrogen in Organic and Organo-Metallic Compounds
This standard is issued under the fixed designation E191; 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 4. Pressure Regulator
1.1 This specification covers apparatus and basic equipment 4.1 The pressure regulator, shown in Fig. 1 and Fig. 2,
for the determination of carbon and hydrogen in organic and consisting of a bell and inlet tube submerged in a suitable
organometallic compounds along the lines of the conventional confining liquid, shall be used to supply air or oxygen, or both,
method of Pregl, but with modifications more in line with at constant pressure to the combustion system. Substitution of
modern practice. Owing to the diversity of apparatus by which a fine gas-control valve and flowmeter for the pressure regu-
correct results can be obtained, this specification is intended to lator is optional.
indicate what is acceptable rather than what is mandatory.
5. Drying and Purifying Tube
NOTE 1—Specifications for several items subsequently listed were
5.1 The conventional bubble-container U-tube shown in
developed by the Committee for the Standardization of Microchemical
Fig. 3 shall be used for drying and purifying the entering air or
Apparatus, Division of Analytical Chemistry, American Chemical Soci-
ety. oxygen, or both.
1.2 The values stated in inch-pound units are to be regarded
6. Flowmeter
as the standard. The metric equivalents of inch-pound units
6.1 The rate of gas flow shall be determined by the bubble
may be approximate.
counter of the bubble-counter U-tube, or by a more accurate
flow-meter, such as the floating ball-in-column.
2. Referenced Documents
2.1 ASTM Standards: 7. Combustion Unit
E124 Specification for Weighing and Drying Apparatus for
7.1 The combustion unit shall consist of a long furnace, a
Microchemical Analysis
sample furnace, a constant-temperature heating mortar, a
E148 Specification for Apparatus for Microdetermination of
combustion tube, and a combustion-tube closure.
Nitrogen by the Dumas Method (Withdrawn 1987)
7.1.1 Long Furnace:
7.1.1.1 The long furnace shall have a maximum over-all
3. Oxygen Supply
length of 8 in. (203 mm) with the wall thickness at the ends not
3.1 Any cylinder or other suitable source of oxygen free of ⁄4 in. (6 mm). The furnace shall accommodate
to exceed
hydrogen and organic impurities may be used. Oxygen pre-
combustion tubes up to 13 mm in outside diameter. Electric
pared from liquid air is satisfactory. heating elements shall be easily replaceable. The furnace shall
be mounted firmly on a substantial support.
7.1.1.2 Thefurnaceshallbecapableofcontinuousoperation
This specification is under the jurisdiction of ASTM Committee E41 on attemperaturesupto900°Casmeasuredinsidethecombustion
Laboratory Apparatus and is the direct responsibility of Subcommittee E41.01 on
tube at the middle of the furnace. The temperature drop from
Laboratory Ware and Supplies.
the center to points 1 in. (25 mm) and 1 ⁄4 in. (45 mm) from
Current edition approved Jan. 1, 2017. Published February 2017. Originally
either end shall not exceed 15 and 7 %, respectively, based
approved in 1962. Discontinued in 1988 and reinstated in 1989. Last previous
edition approved in 2011 as E191 – 64 (2011). DOI: 10.1520/E0191-64R17.
upon the temperature in the middle of the furnace. Means
Committee for the Standardization of Microchemical Apparatus. Division of
shall be provided for varying the temperature.
Analytical Chemistry,American Chemistry Society, 1949 Report on Recommended
Specifications for Microchemical Apparatus, Carbon-Hydrogen, Dumas Nitrogen,
Sulfur, and Halogen, Analytical Chemistry Vol 21, p. 1555 (1949). Furter, M. F., and Steyermark, A., “Pressure Regulator for Use in Microdeter-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or mination of Carbon and Hydrogen,” Analytical Chemistry, Vol 20, 1948, p. 257.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Kuck, J. A., and Altieri, P. L., “Spherical Ground-Glass Joints vs. Rubber
Standards volume information, refer to the standard’s Document Summary page on Tubing Connectors on the C and HAbsorptionTrain,” MikrochimicaActa,1956,p.
the ASTM website. 1556.
The last approved version of this historical standard is referenced on Several types of commercially available electric furnaces meet these require-
www.astm.org. ments.
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E191 − 64 (2017)
FIG. 1 Pressure Regulator, Glass Parts
7.1.1.3 The furnace shall be equipped with some device for mm)/min. An automatic control shall be provided to stop the
indicating the temperature at the middle of the furnace. travel of the sample furnace when it reaches the long furnace.
7.1.2 Sample Furnace, Traveling Type
...