MW-RN-2020 (1)

Protocol for the Collection, Transfer and ANSI/AARST MW-RN 2020 Measurement of Radon in Water 2 SECTION 2.0 DEFINITIONS Accuracy: Closeness of agreement between an observed value and an accepted reference value. Alpha Scintillation Cell: Also known as a Lucas cell, a type of gas chamber that is coated with silver-activated zinc sulfide that scintillates when struck by alpha particles emitted during radon decay. A photomultiplier measures the light pulses that are proportional to the radon content. Blanks: A type of QC check that quantifies detector response due to factors other than the measurement itself. Blanks are devices deployed to measure effects on the measurement result from anything other than the environment tested (e.g., during storage, handling and transport). Calibration: To adjust or determine or both the response or reading of an instrument or device relative to a series of conventionally true values. Calibration Factor: That factor or function that represents the relationship between the method’s response and the concentration to which it is responding. The calibration factor is based on measurement system response divided by the concentration to which it is responding. Continuous Radon Monitor (CRM): An electronic device with adaptations that can provide numeric measurements of radon concentration in a water sample. Cocktail: A vial containing both a water sample and liquid scintillation fluid for the measurement of dissolved radon. Dark adapt: Placement of a liquid scintillation cocktail , prior to measurement, in a holding area with no light for a period (generally 1 to 3 hr) in order to control chemiluminescence and false counts. Duplicates: Two identical samples collected at the same time, using the same procedures and tested separately. Duplicate samples are used to evaluate collection and measurement precision. Electret Ion Chamber (EIC): An ion chamber with a charged electret that discharges, due to the decay of radon and its short-lived progeny, proportionally to the radon level inside the chamber. Intercomparison: A mutual comparison of measurement results that may be used to develop a consensus value. Laboratory: Any person(s) or entity that measures and reports radon levels. Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in drinking water. MCL s take the best available treatment technology and cost into consideration. Method Detection Limit (MDL): The minimum concentration of a substance that can be measured and reported with an established confidence (95% at minimum) that the analyte concentration is greater than zero and is determined from analysis of a sample in a given matrix containing the analyte. Ostwald Solubility Coefficient: A measure of the solubility of radon in water, defined as the ratio of radon concentration in water to radon concentration in air, measured as 0.51 and 0.25 for water temperature of 0°C and 20°C, respectively. PTFE: Polytetrafluoroethylene, popularly known as Teflon™ or Syncolon™, is chemically inert and impervious to radon diffusion. It is used as an alternative to aluminum foil in bottle caps to retard the loss of radon. Qualified Measurement Laboratory: A measurement service that has demonstrated a minimum degree of quality for analysis of measurement samples as demonstrated by: a) successful intercomparisons with other qualified laboratories to indicate a minimum degree of quality for analysis of measured samples. The results of intercomparisons shall be recorded in quality assurance records and made available to the public upon request;