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Improving uncertainty in Widmark equation calculations: Alcohol volume, strength and density
Peter D Maskell1, R Alex Speers2, Dawn L Maskell3
1School of Science, Engineering and Technology, Abertay University, Dundee, Scotland, UK.
Science & Justice : Journal of the Forensic Science Society
|September 12, 2017
Summary
This study refines the Widmark equation for medicolegal alcohol calculations by improving uncertainty estimates. It recommends Monte Carlo Simulation for more accurate forensic measurements in the USA and UK.
Area of Science:
- Forensic Science
- Toxicology
- Analytical Chemistry
Background:
- The Widmark equation is a standard for medicolegal alcohol calculations.
- Recent calls from the National Research Council (USA) and Forensic Science Regulator (UK) emphasize the need for uncertainty quantification in forensic measurements.
- Previous research has addressed some factors influencing Widmark calculations, but uncertainties in specific parameters require further investigation.
Purpose of the Study:
- To enhance the accuracy of Widmark equation calculations by improving the uncertainty of measurement for key parameters.
- To determine revised and improved uncertainties for the concentration of ethanol in Widmark calculations relevant to both the USA and UK.
- To provide a more robust method for forensic alcohol analysis.
Main Methods:
- Experimental studies were conducted to assess measurement uncertainties.
- A comprehensive review of the scientific literature was performed.
- Relevant legal statutes were analyzed to inform the calculations.
- Monte Carlo Simulation was explored for uncertainty determination.
Main Results:
- Revised and improved uncertainties for the concentration of ethanol in Widmark calculations were determined for the USA and UK.
- The study identified specific areas where uncertainty in measurement could be reduced.
- The effectiveness of Monte Carlo Simulation for this application was evaluated.
Conclusions:
- The improved uncertainty estimates enhance the reliability of Widmark calculations for medicolegal purposes.
- Monte Carlo Simulation is recommended as the preferred method for determining measurement uncertainty in Widmark calculations.
- This research contributes to more accurate and defensible forensic alcohol analysis.
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