In this chapter, the following terms have the meanings indicated. Terms Defined. “Agency” means any law enforcement agency approved to test breath or blood for alcohol content. “Alcohol” means ethyl alcohol (ethanol). “Alcohol calibration solution” means a water solution containing a range of certified, specific concentrations of ethanol from 0.02 to 0.500 gram/deciliter for the purpose of ethanol quantitation. “Alcohol control solution” means a water solution containing a certified, specific concentration of ethanol. “Alcohol gas standard” means a container of compressed gas containing a specific concentration of alcohol. “Alcohol reference solution” means a water solution containing a specific concentration of alcohol. “Breath sample” means the amount of breath delivered by the individual being tested that is an adequate volume to be analyzed by the breath testing instrument. “CTAU” means the Chemical Test for Alcohol Unit within the Department of Maryland State Police. “CTAU supervisor” means the individual designated by the Commander or Director of CTAU and approved by the Toxicologist to supervise the CTAU. “Preliminary breath testing (PBT) device” means a portable, roadside screening device approved by the Toxicologist, pursuant to Transportation Article, §16-205.2, Annotated Code of Maryland, for use on individuals stopped for suspicion of driving while impaired or under the influence of alcohol. “Qualified medical person” means an individual permitted by any state to withdraw blood from humans. “Qualified person” has the meaning stated in Courts and Judicial Proceedings Article, §10-304, Annotated Code of Maryland. “Representative of the Toxicologist” means any employee supervised by the Toxicologist or an employee of the Department of State Police designated by the Toxicologist to act as the authorized representative of the Toxicologist. “Toxicologist” means the Chief Toxicologist or State Toxicologist in the Department of State Police Forensic Sciences Division. “Validation test” means a test of specific alcohol concentration used to verify the calibration of a breath testing instrument.