Acronyms and Abbreviations

AAM	annual arithmetic mean
AB	Assembly Bill
AC	alternating current
AEGL	acute exposure guideline levels
AER	annual emissions report
AERMOD	American Meteorological Society/Environmental Protection Agency regulatory model
AIHA	Industrial Hygiene Association
AQ	air quality
AQ-SPEC	Air Quality Sensor Performance Evaluation Center
BC	black carbon
BNSF	Burlington Northern Santa Fe
CAAQS	California Ambient Air Quality Standards
CAPCOA	California Air Pollution Control Officers Association
CalOSHA	California Occupational Health and Safety Administration
CARB	California Air Resources Board
CCD	charge-coupled device
CHD	catalytic desulfurization
CO	carbon monoxide
DOE	Department of Energy
DTLAGS	L-alanine doped triglycine sulfate
EIR	Environmental Impact Report
EPA	Environmental Protection Agency
ERPG	Emergency Response Planning Guidelines
FAQ	frequently-asked questions
FCC	fluid catalytic cracking unit
FEM	Federal equivalent method
FRM	Federal reference method
FTIR	Fourier transform infrared spectroscopy
GB	gigabytes
GHz	gigahertz
GIS	geographic information system
H₂S	hydrogen sulfide
HARP2	Hotspots Analysis and Reporting program
HF	hydrofluoric acid
ICR	Information Collection Request
IDLH	immediately dangerous to life and health
IH	industrial hygiene
LPG	Liquid petroleum gas
LPM	liter per minute
m²/g	square meters per gram
MAC	mass absorption cross-section
MCT	mercury-cadmium-telluride
mg/m³	milligrams/cubic meter
NAAQS	National Ambient Air Quality Standards
NIOSH	National Institute for Occupational Safety and Health
NMHC	non-methane hydrocarbons
NO	nitric oxide
NO₂	nitrogen dioxide
NO_x	oxides of nitrogen
O₃	ozone
OEEHHA	California Office of Environmental Hazard and Health Assessment
OPA	open path analyzers
PAC	protective action criteria
PAH	protective action criteria
PEL	permissible exposure limit
PERP	portable equipment registration program
PM	particulate matter
PM₁₀	particulate matter with aerodynamic diameter of 10 microns and smaller
PM_2.5	particulate matter with aerodynamic diameter of 2.5 microns and smaller
ppb	parts per billion
ppm	parts per million
QA	quality assurance
QAPP	quality assurance project plan
QC	quality control
R1180	Rule 1180
REL	reference exposure level
RH	relative humidity
SCAQMD	South Coast Air Quality Management District
SIC	silicon carbide
SO₂	sulfur dioxide
SOP	standard operating procedure
SRA	Source/Receptor Area
TAC	toxic air contaminant
TBD	to be determined
TEEL	temporary emergency exposure limit
TORC	Torrance Refining Company LLC
TRI	Toxic Release Inventory
TYP	typical
USB	universal serial bus
USEPA	United States Environmental Protection Agency
UTM	Universal Transverse Mercator coordinate system
UV	ultraviolet
UVDOAS	Ultraviolet differential optical absorption spectroscopy
VAC	voltage alternating current
VDC	voltage direct current
VOC	volatile organic compound
WSW	west-southwest
ZnSe	zinc selenide
μg/m³	micrograms per cubic meter

Data Qualifier Flags

There are two types of data flag types: Null flags and Qualifier flags.

Null flag - This type of flag is assigned when a sample is not usable (e.g., low signal, instrument offline for maintenance, etc.).
Qualifier flag - These flags are used to denote there was a procedural or quality assurance issue that happened that could possibly affect the uncertainty or concentration of the value.

Flags can be used in combination if they are non-Null flags. If a Null flag is used, no other flag is necessary, nor should another flag be used since no data are reported.

Flag	Type	Explanation
Below Detection Limit (BDL)	Data Qualifier	Measurement results is below the minimum detection limit (MDL). The compound was not present at a concentration that could be reliably detected. This may mean the compound is present but had interferences present, was below the detection capability of the instrument, or not present at all.
Few Measurements (FEW)	Data Qualifier	Averaging period has between 25% and 75% data completeness - not enough measurements available to create a representative average. There must be at least 75% data completeness in order for a valid, non-qualified average to be created.
Estimated Concentration (J)	Data Qualifier	Indicates an estimated concentration. This flag is used when the concentration is above the detection limit but less than the Practical Quantitation Limit (PQL). The PQL is determined as a multiplier of the method detection limit (eg., 3.5 times) and is considered the lowest concentration that can be accurately measured, as opposed to just detected.
Questionable (Q)	Data Qualifier	Questionable data
Valid (V)	Data Qualifier	Validated data. Data accepted by data validators. The validators have reviewed the data and determined that it is valid.
Maintenance (MNT)	Null Data Qualifier	Indicates the instrument or monitoring site is undergoing maintenance and data collected is not valid data.
Malfunction (MAL)	Null Data Qualifier	A (instrument) malfunction that voids the data has occurred. The operator has determined that the datum is not valid and should be ignored; or the instrument has generated an error code and is not producing valid measurement data.
Quality Assurance / Quality Control (QAQC)	Null Data Qualifier	Instrument off-line for routine quality assurance/quality control activities (e.g., calibration checks, calibrations, audits, etc.)
Insufficient (INS)	Null Data Qualifier	Insufficient Data (cannot calculate). Less than 25% data completeness for the averaging period.
Negative (NEG)	Null Data Qualifier	The measurement exceeds a lower limit and has too negative a value. It is possible to get small negative values under routine conditions, but large negative numbers indicate a problem in the data collection system.
Limit (LIM)	Null Data Qualifier	Data exceed automatic limits for rejection.
Low Signal (L)	Null Data Qualifier	Low signal is generally the result of poor instrument alignment, adverse weather conditions, or an obstruction along the beam path.
Atmospheric Interference (ATM)	Null Data Qualifier	Data invalid - interference due to atmospheric conditions.
Invalid (NVAL)	Null Data Qualifier	Invalid/Null Data. Datum rejected by data validators. The validators have reviewed the datum and determined that it is not valid.
Missing (M)	Null Data Qualifier	Generic "Missing" for data, especially averages, for which the cause of the anomaly has yet to be assigned. Usually indicates that data was never collected. This may also be triggered by delays or breakdowns in data communications.
Power (PWR)	Null Data Qualifier	No power to site. No data collected.