ASTM E131-10(2015)

Standard Terminology Relating to Molecular Spectroscopy

SCOPE
1.1 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

General Information

• Status: Historical
• Publication Date: 30-Apr-2015
• ICS: 01.040.71 - Chemical technology (Vocabularies)
• ICS: 71.040.50 - Physicochemical methods of analysis
• Technical Committee: E13 - Molecular Spectroscopy and Separation Science
• Drafting Committee: E13.94 - Terminology

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E131 − 10 (Reapproved 2015)
Standard Terminology Relating to
1, 2
Molecular Spectroscopy
This standard is issued under the fixed designation E131; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
been effected for reflectance losses, solvent absorption losses, and
1. Scope
refractive effects, if present, and that attenuation by scattering is small
1.1 The values stated in SI units are to be regarded as
comparedwithattenuationbyabsorption.Apparentdeviationsfromthe
standard. No other units of measurement are included in this
absorption laws (see absorptivity) are due to inability to measure
standard.
exactly the true transmittance or to know the exact concentration of an
absorbing substance.
2. Referenced Documents
absorption band—a region of the absorption spectrum in
3
2.1 ASTM Standards:
which the absorbance passes through a maximum.
E135Terminology Relating to Analytical Chemistry for
absorption coefficient, α—a measure of absorption of radiant
Metals, Ores, and Related Materials
energy from an incident beam as it traverses an absorbing
E168Practices for General Techniques of Infrared Quanti-
−αb
4
medium according to Bouguer’s law, P/P = e .
tative Analysis (Withdrawn 2015) o
DISCUSSION—In IRS, α is a measure of the rate of absorption of
E204Practices for Identification of Material by Infrared
energy from the evanescent wave.
Absorption Spectroscopy, Using the ASTM Coded Band
4
and Chemical Classification Index (Withdrawn 2014) absorption parameter, a—the relative reflection loss per
E284Terminology of Appearance
reflection that results from the absorption of radiant energy
E386Practice for Data Presentation Relating to High- at a reflecting surface: a=1− R, and R=the reflected
Resolution Nuclear Magnetic Resonance (NMR) Spec-
fraction of incident radiant power.
troscopy
absorption spectrum—a plot, or other representation, of
E456Terminology Relating to Quality and Statistics
absorbance, or any function of absorbance, against
5
2.2 Other Documents:
wavelength, or any function of wavelength.
ISOGuide30–1981(E)Terms and definitions used in con-
nections with reference materials
absorptivity, a—theabsorbancedividedbytheproductofthe
concentration of the substance and the sample pathlength,
3. Terminology
a=A⁄bc. The units of b and c shall be specified.
DISCUSSION—1—The recommended unit for b is the centimetre. The
absorbance, A—the logarithm to the base 10 of the reciprocal
recommended unit for c is kilogram per cubic metre. Equivalent units
of the transmittance, (T). 3 3
are g/dm , g/L, or mg/cm .
A 5 log ~1/T!52log T (1)
10 10
DISCUSSION—2—The equivalent IUPAC term is “specific absorption
DISCUSSION—In practice the observed transmittance must be substi-
coefficient.”
tuted for T.Absorbance expresses the excess absorption over that of a
specified reference or standard. It is implied that compensation has
absorptivity, molar, ε—the product of the absorptivity, a, and
the molecular weight of the substance.
DISCUSSION—The equivalent IUPAC term is “molar absorption coef-
1
This terminology is under the jurisdiction of ASTM Committee E13 on
ficient.”
Molecular Spectroscopy and Separation Science and is the direct responsibility of
Subcommittee E13.94 on Terminology.
acceptance angle, n—for an optical fiber,themaximumangle,
Current edition approved May 1, 2015. Published June 2015. Originally
measuredfromthelongitudinalaxisorcenterlineofthefiber
approved in 1957. Last previous edition approved in 2010 as E131– 10. DOI:
to an incident ray, within which the ray will be accepted for
10.1520/E0131-10R15.
2
Forotherdefinitionsrelatingtonuclearmagneticresonance,seePracticeE386.
transmission along the fiber by total internal reflection.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DISCUSSION—If the incidence angle exceeds the acceptance angle,
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
optical power in the incident ray will be coupled into leaky modes or
Standards volume information, refer to the standard’s Document Summary page on
rays, or lost by scattering, diffusion, or absorption in the cladding. For
the ASTM website.
a cladded step-index fiber in the air, the sine of the acceptance angle is
4
The last approved version of this historical standard is referenced on
givenbythesquarerootofthedifferenceofthesquaresoftherefractive
www.astm.org.
5
indexes of the fiber core and the cladding, that is, by the relation as
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. follows:
Copyright
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E131 − 10 E131 − 10 (Reapproved 2015)
Standard Terminology Relating to
1, 2
Molecular Spectroscopy
This standard is issued under the fixed designation E131; 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
1.1 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
2. Referenced Documents
3
2.1 ASTM Standards:
E135 Terminology Relating to Analytical Chemistry for Metals, Ores, and Related Materials
4
E168 Practices for General Techniques of Infrared Quantitative Analysis (Withdrawn 2015)
E204 Practices for Identification of Material by Infrared Absorption Spectroscopy, Using the ASTM Coded Band and Chemical
4
Classification Index (Withdrawn 2014)
E284 Terminology of Appearance
E386 Practice for Data Presentation Relating to High-Resolution Nuclear Magnetic Resonance (NMR) Spectroscopy
E456 Terminology Relating to Quality and Statistics
5
2.2 Other Documents:
ISO Guide 30–1981 (E) Terms and definitions used in connections with reference materials
3. Terminology
absorbance, A—the logarithm to the base 10 of the reciprocal of the transmittance, (T).
A 5 log 1/T 52log T (1)
~ !
10 10
1
This terminology is under the jurisdiction of ASTM Committee E13 on Molecular Spectroscopy and Separation Science and is the direct responsibility of Subcommittee
E13.94 on Terminology.
Current edition approved March 1, 2010May 1, 2015. Published April 2010June 2015. Originally approved in 1957. Last previous edition approved in 20052010 as
E131 – 05.E131 – 10. DOI: 10.1520/E0131-10.10.1520/E0131-10R15.
2
For other definitions relating to nuclear magnetic resonance, see Practice E386.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
4
The last approved version of this historical standard is referenced on www.astm.org.
5
Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http://www.ansi.org.
DISCUSSION—
In practice the observed transmittance must be substituted for T. Absorbance expresses the excess absorption over that of a specified reference or
standard. It is implied that compensation has been effected for reflectance losses, solvent absorption losses, and refractive effects, if present, and that
attenuation by scattering is small compared with attenuation by absorption. Apparent deviations from the absorption laws (see absorptivity) are due
to inability to measure exactly the true transmittance or to know the exact concentration of an absorbing substance.
absorption band—a region of the absorption spectrum in which the absorbance passes through a maximum.
absorption coefficient, α—a measure of absorption of radiant energy from an incident beam as it traverses an absorbing medium
−αb
according to Bouguer’s law, P/P = e .
o
DISCUSSION—
In IRS, α is a measure of the rate of absorption of energy from the evanescent wave.
absorption parameter, a—the relative reflection loss per reflection that results from the absorption of radiant energy at a reflecting
surface: a = 1 − R, and R = the reflected fraction of incident radiant power.
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1

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E131 − 10 (2015)
absorption spectrum—a plot, or other representation, of absorbance, or any function of absorbance, against wavelength, or any
function of wavelength.
absorptivity, a— the absorbance divided by the product of the concentration of the substance and the sample pathlength, a = A ⁄bc.
The units of b and c shall be specified.
DISCUSSION—
3 3
1—The recommended unit for b is the centimetre. The recommended unit for c is kilogram per cubic metre. Equivalent units are g/dm , g/L, or mg/cm .
DISCUSSION—
2—The equivalent IUPAC term is “specific absorption coefficient.”
absorptivity, molar, ε—the product of the absorptivity, a, and the molecular weight of the substance.
DISCUSSION—
The equivalent IUPAC term is “molar absorption coefficient.”
acceptance angle, n—for an optical fiber, the maximum angle, measured from the lon
...