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Why the Limit of Detection (LOD) Value is Not an Appropriate Specification for Automotive Emissions Analyzers
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 21, 2002 by SAE International in United States
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With the need for emission measurements of super ultra low emission vehicles (SULEV), analyzer manufacturers have been required to produce more precise and accurate analyzers. In order to compare analyzers, the customer must understand the different specifications used by the analyzer manufacturers. One specification that some manufacturers have used is the limit of detection (LOD) to indicate the reliability of the analyzer output at low concentrations.
There are various methods for determining the LOD for a given analyzer. The authors will demonstrate how variations in methodology can produce different LOD values for a specific analyzer and what it means for the automotive emission analyzers. It is also demonstrated that the standard deviations of a zero signal, which is related to LOD, can be heavily influenced by data processing, such as data length in use and/or data smoothing. The LOD values obtained will be compared to the limit of quantification (LOQ) for that analyzer. In order to evaluate the utility of LOD measurements, various analyzer performances will be modeled and evaluated.
While the LOD is a valid statistical approach to determining the presence of a component in a sample matrix, it is not directly applicable to emissions measurements. A discussion about the emission measurement requirements will demonstrate the limited applicability of this analyzer specification. Alternative methods for comparing analyzer specifications will be presented and justified.
CitationAkard, M., Tsurumi, K., Oestergaard, K., and Inoue, K., "Why the Limit of Detection (LOD) Value is Not an Appropriate Specification for Automotive Emissions Analyzers," SAE Technical Paper 2002-01-2711, 2002, https://doi.org/10.4271/2002-01-2711.
SAE 2002 Transactions Journal of Fuels and Lubricants
Number: V111-4; Published: 2003-09-15
Number: V111-4; Published: 2003-09-15
- Inoue K. et. al. Numerical Analysis of Mass Emission Measurement Systems for Low Emission Vehicles SAE paper 1999-01-0150
- Sherman M. T. et. al. Error Analysis of Various Sampling Systems SAE 2001-01-0209
- Landry M. et. al. Simulation of Low Level Vehicle Exhaust Emissions for Evaluation of Sampling and Analytical Systems SAE paper 2001-01-0211
- Guenther M. et. al. Advanced Emissions Test Site for Confident PZEV Measurements SAE Paper 2002-01-0046
- Behrendt H. et. al. Studies on Enhanced CVS Technology to Achieve SULEV Certification SAE 2002-01-0048
- Guenther M. et. al. Improved Bag Mini-diluter Sampling System for Ultra-low Level Vehicle Exhaust Emissions SAE Paper 2000-01-0792
- Nagy D. B. et. al. Evaluation of the Bag Mini-Diluter and Direct Vehicle Exhaust Volume System for Low Level Emissions Measurement SAE Paper 2000-01-0793
- Guenther M. et. al. Refinement of a Bag Mini-Diluter System SAE Paper 2001-01-0212
- Kaiser H. Anal. Chem. 1987 42 53A
- Long G.L. Winefordner J.D. Anal. Chem. 1983 55 712A
- Taylor “Quality Assurance of Chemical Measurements,” Lewis Publishers, Inc. 1987
- Basic Gas Chromatography McNair H. Bonelli E. 5th Varian Aerograph 1969 87
- Pierburg AVL SAE 2001 booth literature
- “Procedure for LOD Determination for Speciated Hydrocarbon Analysis (MLD Method 1002/1003),” California Air Resources Board 1999
- Taylor B. Kuyatt C. Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results NIST Technical Note 1297 1994 4
- Feller W. An Introduction to Probability Theory and Its Applications 1 3rd New York Wiley 1968
- CFR 40, §86.121-90(b)(3)
- CFR 40, §86.122-90(b)(3)
- CFR 40, §86.123-78(b)(3)
- CFR 40, §86.124-78(c)
- CFR 40, §86.125-94(c)
- Principles of Instrumental Analysis Skoog D. Leary J. 4th Saunders College Publishing 1992 8
- CFR 40, §86.114-94(8)
- Tayama A. et. al. A Study of a Gasoline-Fueled Near-Zero-Emission Vehicle Using an Improved Emission Measurement System SAE Paper, 982555
- Sun E.I. et. al. Evaluation of Fluorocarbon Polymer Bag Material for Near Zero Exhaust Emission Measurement SAE paper 2001-01-3535
- Hill J. et. al. Evaluation of New Bag Sampling Materials for Low Level Emissions Measurements SAE paper 2002-01-0051
- Data Handling in Science and Technology Chemometrics: a Textbook Massart et. al. 2 Elsevier Science Publishers B.V. 1988 16
- Taylor B. Kuyatt C. Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results NIST Technical Note 1297 1994 21