Symbols and Abbreviations

B L —Analyzer reading at the specified LDL test concentration for the LDL test. B Z —analyzer reading at 0 concentration for the LDL test. DM —Digital meter. C max —Maximum analyzer reading during the 12 ZD test period. C min —Minimum analyzer reading during the 12 ZD test period. i —Subscript indicating the i -th quantity in a series. IE —Interference equivalent. L 1 —First analyzer zero reading for the 24 ZD test. L 2 —Second analyzer zero reading for the 24 ZD test. n —Subscript indicating the test day number. P —Analyzer reading for the span drift and precision tests. P i —The i -th analyzer reading for the span drift and precision tests. P 20 —Precision at 20 percent of URL. P 80 —Precision at 80 percent of URL. ppb—Parts per billion of pollutant gas (usually in air), by volume. ppm—Parts per million of pollutant gas (usually in air), by volume. R —Analyzer reading of pollutant alone for the IE test. R 1 —Analyzer reading with interferent added for the IE test. r i —the i -th analyzer or DM reading for the noise test. S —Standard deviation of the noise test readings. S 0 —Noise value ( S ) measured at 0 concentration. S 80 —Noise value ( S ) measured at 80 percent of the URL. S n —Average of P 7 . . . P 12 for the n-th test day of the SD test. S' n —Adjusted span reading on the n -th test day. SD—Span drift URL —Upper range limit of the analyzer's measurement range. Z —Average of L 1 and L 2 readings for the 24ZD test. Z n —Average of L 1 and L 2 readings on the n -th test day for the 24ZD test. Z' n —Adjusted analyzer zero reading on the n -the test day for the 24ZD test. ZD —Zero drift. 12 ZD —12-hour zero drift. 24 ZD —24-hour zero drift.