ASTM D4430-00(2010)

Standard Practice for Determining the Operational Comparability of Meteorological Measurements

SIGNIFICANCE AND USE
This practice provides data needed for selection of instrument systems to measure meteorological quantities and to provide an estimate of the precision of measurements made by such systems.
This practice is based on the assumption that the repeated measurement of a meteorological quantity by a sensor system will vary randomly about the true value plus an unknowable systematic difference. Given infinite resolution, these measurements will have a Gaussian distribution about the systematic difference as defined by the Central Limit Theorem. If it is known or demonstrated that this assumption is invalid for a particular quantity, conclusions based on the characteristics of a normal distribution must be avoided.
SCOPE
1.1 Sensor systems used for making meteorological measurements may be tested for laboratory accuracy in environmental chambers or wind tunnels, but natural exposure cannot be fully simulated. Atmospheric quantities are continuously variable in time and space; therefore, repeated measurements of the same quantities as required by Practice E177 to determine precision are not possible. This practice provides standard procedures for exposure, data sampling, and processing to be used with two measuring systems in determining their operational comparability (1,2).  
1.2 The procedures provided produce measurement samples that can be used for statistical analysis. Comparability is defined in terms of specified statistical parameters. Other statistical parameters may be computed by methods described in other ASTM standards or statistics handbooks (3).
1.3 Where the two measuring systems are identical, that is, same make, model, and manufacturer, the operational comparability is called functional precision.
1.4 Meteorological determinations frequently require simultaneous measurements to establish the spatial distribution of atmospheric quantities or periodically repeated measurement to determine the time distribution, or both. In some cases, a number of identical systems may be used, but in others a mixture of instrument systems may be employed. The procedures described herein are used to determine the variability of like or unlike systems for making the same measurement.
1.5 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. (See 8.1 for more specific safety precautionary information.)

General Information

• Status: Historical
• Publication Date: 30-Sep-2010
• ICS: 07.060 - Geology. Meteorology. Hydrology
• Technical Committee: D22 - Air Quality
• Drafting Committee: D22.11 - Meteorology

Relations

• Replaces: ASTM D4430-00(2006) - Standard Practice for Determining the Operational Comparability of Meteorological Measurements
• Effective Date: 01-Oct-2010

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: D4430 − 00(Reapproved 2010)
Standard Practice for
Determining the Operational Comparability of
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Meteorological Measurements
This standard is issued under the fixed designation D4430; 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 2. Referenced Documents
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2.1 ASTM Standards:
1.1 Sensor systems used for making meteorological mea-
surements may be tested for laboratory accuracy in environ- D1356 Terminology Relating to Sampling and Analysis of
Atmospheres
mental chambers or wind tunnels, but natural exposure cannot
be fully simulated. Atmospheric quantities are continuously E177 Practice for Use of the Terms Precision and Bias in
ASTM Test Methods
variable in time and space; therefore, repeated measurements
of the same quantities as required by Practice E177 to
3. Terminology
determine precision are not possible. This practice provides
3.1 For additional definitions of terms, refer toTerminology
standard procedures for exposure, data sampling, and process-
D1356.
ingtobeusedwithtwomeasuringsystemsindeterminingtheir
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operational comparability (1,2).
3.2 Definitions of Terms Specific to This Standard:
3.2.1 difference (D)—the difference between the systematic
1.2 The procedures provided produce measurement samples
difference (d) of a set of samples and the true mean (µ) of the
that can be used for statistical analysis. Comparability is
population:
defined in terms of specified statistical parameters. Other
statistical parameters may be computed by methods described
D 5 d 2 µ (1)
in other ASTM standards or statistics handbooks (3).
3.2.2 systematic difference (d)—the mean of the differences
1.3 Where the two measuring systems are identical, that is, in the measurement by the two systems:
same make, model, and manufacturer, the operational compa-
N
1
rability is called functional precision. d 5 X 2 X (2)
~ !
( ai bi
N
i51
1.4 Meteorologicaldeterminationsfrequentlyrequiresimul-
3.2.3 operational comparability (C)—the root mean square
taneous measurements to establish the spatial distribution of
(rms) of the difference between simultaneous readings from
atmosphericquantitiesorperiodicallyrepeatedmeasurementto
two systems measuring the same quantity in the same environ-
determine the time distribution, or both. In some cases, a
ment:
number of identical systems may be used, but in others a
N
mixture of instrument systems may be employed. The proce- 1
2
C56Π~X 2 X ! (3)
( ai bi
dures described herein are used to determine the variability of N
i51
like or unlike systems for making the same measurement.
where:
1.5 This standard does not purport to address the safety
X = ith measurement made by one system,
ai
concerns, if any, associated with its use. It is the responsibility
X = ith simultaneous measurement made by another
bi
of the user of this standard to establish appropriate safety and
system, and
health practices and determine the applicability of regulatory
N = number of samples used.
limitations prior to use. (See 8.1 for more specific safety
3.2.3.1 functional precision—the operational comparability
precautionary information.)
of identical systems.
3.2.4 estimated standard deviation of the difference (s)—a
measureofthedispersionofaseriesofdifferencesaroundtheir
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This practice is under the jurisdiction ofASTM Committee D22 on Air Quality
mean.
and is the direct responsibility of Subcommittee D22.11 on Meteorology.
Current edition approved Oct. 1, 2010. Published March 2011. Originally
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approved in 1984. Last previous edition approved in 2006 as D4430 - 00(2006). For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/D4430-00R10. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
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The boldface numbers in parentheses refer to the list of references at the end of Standards volume information, refer to the standard’s Document Summary page on
this practice. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D4430 − 00 (2010)
2 2 low-wind speeds). To test the data for such dependence, the
s56=C 2 d (4)
range of measurements shall be divided into no less than three
3.2.5 skewness (M)—the symmetry of the distribution (the
class intervals and each class shall have a sufficient number of
third moment about the mean).
samples to represent the class. The change in rms difference
N
between classes indicates the dependence of the measurement
3
X 2 X 2 d
~~ ! !
( ai bi
difference on the magnitude of th
...