Table B-5 to Subpart B of Part 53 - Symbols and Abbreviations
BL - Analyzer reading at the specified LDL test concentration for the LDL test.
BZ - analyzer reading at 0 concentration for the LDL test.
DM - Digital meter.
Cmax - Maximum analyzer reading during the 12ZD test period.
Cmin - Minimum analyzer reading during the 12ZD test period.
i - Subscript indicating the i-th quantity in a series.
IE - Interference equivalent.
L1 - First analyzer zero reading for the 24ZD test.
L2 - Second analyzer zero reading for the 24ZD test.
n - Subscript indicating the test day number.
P - Analyzer reading for the span drift and precision tests.
Pi - The i-th analyzer reading for the span drift and precision tests.
P20 - Precision at 20 percent of URL.
P80 - 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.
R1 - Analyzer reading with interferent added for the IE test.
ri - the i-th analyzer or DM reading for the noise test.
S - Standard deviation of the noise test readings.
S0 - Noise value (S) measured at 0 concentration.
S80 - Noise value (S) measured at 80 percent of the URL.
Sn - Average of P7 . . . P12 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 L1 and L2 readings for the 24ZD test.
Zn - Average of L1 and L2 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.
12ZD - 12-hour zero drift.
24ZD - 24-hour zero drift.