[Comparative measurements with breath alcohol measuring devices].

Area of Science:

• Forensic Science
• Analytical Chemistry
• Toxicology

Background:

• Breath-alcohol analyzers are crucial for law enforcement and clinical settings.
• Ensuring the accuracy and reliability of these devices is paramount for forensic applicability.
• Regulatory bodies like the Federal Health Office set essential requirements for breath analysis instruments.

Purpose of the Study:

• To assess the performance and precision of two different breath-alcohol analyzers.
• To compare measuring systems, including infrared and fuel cell technologies.
• To evaluate the forensic applicability of the tested breathalyzers.

Main Methods:

• A drinking experiment involving 12 participants was conducted.
• Two distinct breath-alcohol analyzers were tested, one with dual infrared and fuel cell systems, the other with a single infrared system.
• Breath temperature and volume were measured to standardize breath alcohol concentration (BrAC) to 34°C.

Main Results:

• Both instruments met essential requirements for forensic use.
• The precision of all tested systems was high, characterized by a standard deviation of less than 0.01 mg/l.
• BrAC values were comparable after standardization to a reference temperature.

Conclusions:

• The evaluated breath-alcohol analyzers exhibit excellent measuring precision suitable for forensic applications.
• Both infrared and fuel cell technologies, when properly implemented, provide reliable breath alcohol measurements.
• The study supports the forensic applicability of modern breathalyzer technology.