Performance-Specifications-for-Instrumentation-Systems

MS-PC 2015: Performance Specifications for Instrumentation Systems Designed to Measure Radon Gas in Air Page 7 of 20 5 UNIT ABBREVIATIONS & CONVERSIONS The units used in this standard, abbreviations of those units, and some conversions between traditional units and those of the International System of Units (SI) are listed in Table 5.1. Table 5.1 Unit abbreviations and conversions Unit & Abbreviation Conversion becquerel (Bq) – a unit of activity 1 Bq = 1 disintegration per second = 27 pCi becquerel per cubic meter (Bq/m 3 ) – a unit of activity concentration 1 Bq/m 3 = 0.027 pCi/L becquerel-hours per cubic meter (Bq-h/m 3 ) – a unit of integrated concentration 1 Bq-h/m 3 = 0.00113 pCi- d/L counts per hour (cph) – a unit of rate of observed counts 1 cph = 0.0167 cpm counts per minute (cpm) – a unit of rate of observed counts 1 cpm = 60 cph curie (Ci) – a unit of activity 1 Ci = 3.7x10 10 Bq hour (h) – a unit of time 1 h = 60 min liter (L) – a unit of volume 1 L = 1,000 cm 3 minute (min) – a unit of time 1 min = 0.0167 h picocurie (pCi) – a unit of activity 1 pCi = 0.037 Bq picocuries per liter (pCi/L) – a unit of activity concentration 1 pCi/L = 37 Bq/m 3 picocurie-days per liter (pCi-d/L) – a unit of integrated concentration 1 pCi-d/L = 888 Bq-h/m 3 6 CLASSIFICATION OF INSTRUMENT SYSTEMS The minimum performance criteria and testing requirements specified in this standard are consistent for all methods, with the exception of two additional requirements for continuous radon monitors used for measurements over 1-hour intervals. These additional requirements pertain to the calibration factor and the minimum detectable concentration (MDC). These requirements are discussed further in Section 6.1. The following brief descriptions of the various types of devices or measurement systems are included here primarily as information supplemental to this standard. 6.1 Continuous Radon Monitors For the purpose of this standard, a Continuous Radon Monitor (CRM) is an electronic instrument that is capable of providing reviewable, numeric values of radon concentration in air at intervals of 1 hour or less and can meet the criteria contained in the definition of a CRM in Section 4. Described below are three types of CRMs that differ by the mechanism used to detect radiation from radon and/or its progeny. This standard does not exclude