ASTM E925-02

Standard Practice for Monitoring the Calibration of Ultraviolet-Visible Spectrophotometers whose Spectral Slit Width does not Exceed 2 nm

SIGNIFICANCE AND USE
This practice permits an analyst to compare the performance of an instrument to the manufacturer’supplied performance specifications and to verify its suitability for continued routine use. It also provides generation of calibration monitoring data on a periodic basis, forming a base from which any changes in the performance of the instrument will be evident.
SCOPE
1.1 This practice covers the parameters of spectrophotometric performance that are critical for testing the adequacy of instrumentation for most routine tests and methods within the wavelength range of 200 to 700 nm and the absorbance range of 0 to 2. The recommended tests provide a measurement of the important parameters controlling results in spectrophotometric methods, but it is specifically not to be inferred that all factors in instrument performance are measured.
1.2 This practice may be used as a significant test of the performance of instruments for which the spectral slit width does not exceed 2 nm and for which the manufacturer's specifications for wavelength and absorbance accuracy do not exceed the performance tolerances employed here. This practice employs an illustrative tolerance of ± 1 % relative for the error of the absorbance scale over the range of 0.2 to 2.0, and of 1.0 nm for the error of the wavelength scale. A suggested maximum stray radiant power ratio of 4 x 10-4 yields
1.3 This practice should be performed on a periodic basis, the frequency of which depends on the physical environment within which the instrumentation is used. Thus, units handled roughly or used under adverse conditions (exposed to dust, chemical vapors, vibrations, or combinations thereof) should be tested more frequently than those not exposed to such conditions. This practice should also be performed after any significant repairs are made on a unit, such as those involving the optics, detector, or radiant energy source.
1.4 This standard does not purport to address all of 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.

General Information

• Status: Historical
• Publication Date: 09-Mar-2002
• ICS: 17.180.30 - Optical measuring instruments
• ICS: 71.040.50 - Physicochemical methods of analysis
• Technical Committee: E13 - Molecular Spectroscopy and Separation Science
• Drafting Committee: E13.01 - Ultra-Violet, Visible, and Luminescence Spectroscopy

Relations

• Replaces: ASTM E925-83(1994)e1 - Standard Practice for Monitoring the Calibration of Ultraviolet-Visible Spectrophotometers whose Spectral Slit Width does not Exceed 2 nm
• Effective Date: 10-Mar-2002
• Replaced By: ASTM E925-09 - Standard Practice for Monitoring the Calibration of Ultraviolet-Visible Spectrophotometers whose Spectral Slit Width does not Exceed 2 nm
• Effective Date: 01-Oct-2009
• Referred By: ASTM D8470-22 - Standard Practice for Development and Implementation of Instrument Performance Tests for Use on Multivariate Online, At-Line and Laboratory Spectroscopic Based Analyzer Systems
• Effective Date: 10-Mar-2002
• Referred By: ASTM E1341-16(2020) - Standard Practice for Obtaining Spectroradiometric Data from Radiant Sources for Colorimetry
• Effective Date: 10-Mar-2002
• Referred By: ASTM ISO/ASTM51205-17 - Standard Practice for Use of a Ceric-Cerous Sulfate Dosimetry System
• Effective Date: 10-Mar-2002
• Referred By: ASTM ISO/ASTM51401-13 - Standard Practice for Use of a Dichromate Dosimetry System
• Effective Date: 10-Mar-2002
• Referred By: ASTM ISO/ASTM51538-17 - Standard Practice for Use of the Ethanol-Chlorobenzene Dosimetry System
• Effective Date: 10-Mar-2002
• Referred By: ASTM E1866-97(2021) - Standard Guide for Establishing Spectrophotometer Performance Tests
• Effective Date: 10-Mar-2002
• Referred By: ASTM ISO/ASTM51026-15 - Standard Practice for Using the Fricke Dosimetry System
• Effective Date: 10-Mar-2002
• Referred By: ASTM E169-16(2022) - Standard Practices for General Techniques of Ultraviolet-Visible Quantitative Analysis
• Effective Date: 10-Mar-2002
• Referred By: ASTM ISO/ASTM51310-22 - Standard Practice for Use of a Radiochromic Optical Waveguide Dosimetry System
• Effective Date: 10-Mar-2002
• Referred By: ASTM E2153-01(2023) - Standard Practice for Obtaining Bispectral Photometric Data for Evaluation of Fluorescent Color
• Effective Date: 10-Mar-2002
• Referred By: ASTM D5831-17 - Standard Practice for Screening Fuels in Soils
• Effective Date: 10-Mar-2002
• Referred By: ASTM G178-16(2023) - Standard Practice for Determining the Activation Spectrum of a Material (Wavelength Sensitivity to an Exposure Source) Using the Sharp Cut-On Filter or Spectrographic Technique
• Effective Date: 10-Mar-2002
• Referred By: ASTM E1164-12(2023)e1 - Standard Practice for Obtaining Spectrometric Data for Object-Color Evaluation
• Effective Date: 10-Mar-2002

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:E925–02
Standard Practice for
Monitoring the Calibration of Ultraviolet-Visible
Spectrophotometers whose Spectral Slit Width does not
1
Exceed 2 nm
This standard is issued under the fixed designation E925; 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.
INTRODUCTION
In the application of spectrophotometric methods of analysis it is the responsibility of the analyst
to verify and validate that the instrument is functioning properly and is capable of providing
acceptable analytical results. It is preferable that the verification of instrument performance be
accomplished through the use of reference materials whose properties have been accurately
determined.Suchmaterialsarereadilyavailable,andtheiruseinthetestsandmeasurementsdescribed
inthispracticeissatisfactoryforevaluatingtheperformanceofspectrophotometerswhosespectralslit
width does not exceed the value for which the intrinsic or certified properties are valid.Acompromise
maximumpermissiblespectralslitwidthof2nmisrecommendedforthereferencematerialsanderror
tolerances recommended here.
This practice covers some of the essential instrumental parameters that should be evaluated to
ensure the acceptability of the analytical data routinely obtained on the instrument. These parameters
include the accuracy of the wavelength and absorbance scales and stray radiant power levels.
The accuracy of the wavelength scale in both the UV and visible regions is determined using the
sharp absorption bands of a holmium oxide glass or solution filter. The absorbance scale accuracy in
the UV region (235–350 nm) is determined using acidic solutions of potassium dichromate. In the
visibleregion(440–635nm)theabsorbanceaccuracyisdeterminedusingindividuallycertifiedneutral
density glass filters. The use of these reference materials provides a valid and relatively simple means
to test the errors in the wavelength and absorbance scales of small spectral slit width spectrophotom-
eters in the spectral ranges indicated. A simplified version of the opaque filter method is provided as
a test for excessive stray radiant energy.
1. Scope 1.2 This practice may be used as a significant test of the
performance of instruments for which the spectral slit width
1.1 This practice covers the parameters of spectrophotomet-
does not exceed 2 nm and for which the manufacturer’s
ric performance that are critical for testing the adequacy of
2
specifications for wavelength and absorbance accuracy do not
instrumentation for most routine tests and methods within the
exceed the performance tolerances employed here. This prac-
wavelength range of 200 to 700 nm and the absorbance range
tice employs an illustrative tolerance of 61 % relative for the
of0to2.Therecommendedtestsprovideameasurementofthe
error of the absorbance scale over the range of 0.2 to 2.0, and
important parameters controlling results in spectrophotometric
of 61.0 nm for the error of the wavelength scale.Asuggested
methods, but it is specifically not to be inferred that all factors
-4
maximum stray radiant power ratio of 4 3 10 yields <1 %
in instrument performance are measured.
absorbance bias at an absorbance of 2. These tolerances are
chosen to be compatible with many chemical applications
while comfortably exceeding the uncertainty of the certified
1
This practice is under the jurisdiction of ASTM Committee E13 on Molecular
values for the reference materials and typical manufacturer’s
SpectroscopyandisthedirectresponsibilityofSubcommitteeE13.01onUltraviolet
specifications for error in the wavelength and absorbance
and Visible Spectroscopy.
Current edition approved March 10, 2002. Published May 2002. Originally
scales of the instrument under test. The user is encouraged to
´1
published as E925 – 83. Last previous edition D925 – 83 (1994) . DOI: 10.1520/
develop and use tolerance values more appropriate to the
E0925-02.
2
requirements of the end use application. This procedure is
Routine tests are defined as those in which absorbance data obtained on a
sample are compared to those of a standard sample preparation. designed to verify quantitative performance on an ongoing
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E925–02
basis and to compare one instrument’s performance with that 4. Significance and Use
of other similar units. Refer to Practice E275 to extensively
4.1 This practice permits an analyst to compare the perfor-
evaluate the performance of an instrument.
mance of an instrument to the manufac
...