SRPMIC Ozone Monitoring Sites Senior Center SiteHigh School Site Red Mountain Site Lehi Site

Raw Data Traces Back to SRP Standard Reference Photometer (SRP) Ozone Primary Standard Ozone Transfer Standard Ozone Monitor Ozone Raw Data

13.Correct the concentration measured by the DAS by applying the latest calibration equation as: = where: Cda = the corrected concentration from the DAS (ppm), Cd = the measured concentration from the DAS (ppm), a = the intercept of the DAS calibration curve, and b = the slope of the DAS calibration curve. Referenced to QA Handbook for Air Pollution Measurement Systems, Volume II, Ambient Air Quality Monitoring Program, EPA-454/B Section 12.2 when the calibration curve is subsequently used to compute concentration measurements x = (y - a)/m where y represents the analyzer response reading, a is the intercept and m is the slope, Section 12.4 EPA suggests the ambient readings be calculated from the most recent multipoint calibration curve or from a fixed nominal or universal calibration curve, and Section 12.5 Data Reduction Using Calibration Information. 14.Calculate the percent difference between the actual ozone concentration ( Ci ) and the corrected DAS concentration ( Cd ) for the audit and span concentrations as: Percent Difference = x 100% 15. Record all values on the "zero/span check and QC check" worksheet and the precision check control chart. Compare the percent difference with the quality control limits specified in the project Quality Assurance Plan. If the difference is outside of the limits, perform the necessary corrective action. Intercept value from Analyzer’s calibration curve Slope value from Analyzer’s calibration curve Raw data value

Statements from QA Handbook Volume II Calibration relationship are applied to analyzer responses to determine actual concentration Ideally, all ambient measurements obtained from an analyzer should be calculated on the basis of the most recent multi-point calibration The calibration slope and intercept used to calculate ambient measurements are updated only for major calibration When this calibration relationship is subsequently used to compute concentration measurements (x) from analyzer response reading (y), the formula is transposed to form, x = (y – b)/m.

It all starts with Transfer Standard’s certification Transfer Standard Certification Primary Standard Transfer Standard Make:API 400EMake:TECO 49C-PS S/N:1900S/N: Certified: DateSlopeInterceptCorrelatation 12/1/ /2/ /3/ /4/ /11/ /23/ /19/ /25/ /18/ /3/ /26/ /10/ /8/ /30/ AVG: STDEV: AQP\AIR MONITORING\Data Records Management\Certification\Ozone\75056 TS\TS Slope Records Average Slope and Intercept

Created slope & intercept from site monitor calibration Transfer Standard’s slope and intercept is integrated to calculate in the ozone Multi-Point Calibration Slope and intercept is created from site monitor Multi- Point Calibration Calibration relationships of slope & intercept are calculated to analyzer’s raw data to determine actual concentration

Data Correction in E-DAS Network when applying calibration relationship to actual concentration units

Process of correcting ambient data to actual data Example Ambient data is.0302 ppm (parts per million) Apply most recent analyzer calibration curve slope and intercept (1.001 and ) to calculate ambient data.0302 ppm and to determine the actual concentrations would be.0304 ppm ( )/ =.0304 ppm raw data – intercept slope EPA data reports are truncated

Sample of QC Data corrected to actual

Ozone Reporting Data to EPA Most Agency Data Report Report ambient data Ambient Data SRPMIC Data Report to EPA Report data that is actual concentration Correct ambient data to calibration relationship Ambient Data

Purpose Data is Corrected to Actual from Raw Have confidence data is corrected to the next level Data is fine tuned even though not much difference from raw data Data is more defensible especially when it is certified We maybe doing extra steps in adjusting data than other agencies but it is worth reporting actual data

Air Quality/Monitoring Staff Stan Belone, Environmental Engineer Mangas Slinkey, Senior Environmental Specialist Shimmy Smith, Environmental Specialist Administration Chris Horan, Manager, Environmental Protection & Natural Resources