OZONE PROJECT (Digital Ozone analyzer,UV-Digital Ozone monitor)
Ozone Data Validation & Analysis Performed by SCAQMD
description
Transcript of Ozone Data Validation & Analysis Performed by SCAQMD
Presented by: Mike HamdanSouth Coast Air Quality Management DistrictDiamond Bar, CA
Presented at:The Tribal Air Monitoring Training , Pechanga Reservation, CA
South Coast AQMDSouth Coast AQMD
L o s A n g e le sC o u n ty
O ra n g eC o u n ty
R iv e rs id eC o u n ty
S a n B e r n a rd in oC o u n ty
South Coast Basin:4-county region10,000 sq. miles16½ million residentsHundreds of thousands of
diesel vehicles11,000,000 gasoline vehiclesCombined Ports of Long Beach and
Los Angeles = nation's largest cargo gateway
Science & Technology AdvancementScience & Technology Advancement Atmospheric Atmospheric
MeasurementsMeasurements Air Monitoring NetworkAir Monitoring Network Special MonitoringSpecial Monitoring
Instruments ConfigurationZero Air
Generator
Ozone
ESC Data Logger (8832)
Video Chart Recorder (Chessell) Generator
Instrument Manifold
Multi-Gas Calibrator
Minute Polling
Database
Sampling Probe
Ozone StandardsTransfer standards (different levels)– a
transportable device or apparatus that is capable of accurately producing or assaying ozone concentrations. These types of instruments undergo a certification process.
Primary standards – a device capable of assaying ozone concentrations by UV photometry in accordance with the Code of Federal Regulations, part 50, Appendix D (40CFR50).
Certification/VerificationCalibration - establishes a correction factor
to adjust or correct the output of an instrument. This is determined through a comparison between an instrument and SRP at varying levels of ozone.
Certification - establishes traceability of a transfer standard to the SRP. The certification of an instrument requires the results of six calibrations to meet requirements established by U.S. EPA.
Continued.Verification - establishes comparability of a
primary standard to the SRP. The verification of an instrument requires the results of one calibration to meet requirements established by U.S. EPA; however, the output of the instrument is not to be corrected based upon the results of the calibration.
O3 standards certification and verifications
Primary O3 standard is compared with R9 SRP (standard reference photometer) annually.
O3 field standards (Transfer Standards)are certified every 3 months using verified primary standard.
Flow standards are certified against NIST standards annually.
Station Instrument verification & Calibration
Daily zero and span except for Tuesday. Weekly zero and precision check (every
Tuesday)O3 instrument multi-point calibration every 6
months or as needed. (as is then final)Gas calibrator (flow controller & O3
generator) certification every 6 months (as is then final).
Data Validation Levels3 data validation levels.Level I is done by the station operator.
Review chessell data, complet field data sheets, note zero and span values that are exceeding the control limits, document problem with the instruments, document any unusual events at or near the site.
Level II & III data validationLevel II and III are done by office staff. Review data in time series plots.Backfill missing data from back up system. Comparison of current data with historical
data.Compare Ozone concentration to
meteorology and to ozone reading from nearby sites.
Assign data flags due to fires, construction.
Data ScreeningReview data that exceeds historical data max.
from the site.Determine if consecutive equal data values
are valid.Check if data falls outside the calibrated
range.Check for blocks of missing data.Check for consistency of data with season
and time of day.
Data InvalidationIf pc/span values are outside +/- 7 %.Not enough data points to calculate valid
hourly average.Station temperatures are not within 20-30
Deg. C.Data produced during calibration, audit, and
maintenance that are not flag by the data logger with proper invalid flag.
Contact Information
Mike HamdanSouth Coast Air Quality Management District
[email protected]: (909) 396-2267
Cell: (909) 967-492315