Ozone Data Corrections

Salt River Pima Maricopa Indian Community

Community Development Department

Environmental Protection & Natural Resources Air Quality Program

National Tribal Forum – May 13 - 15, 2014

SRPMIC is located in Scottsdale, AZ

SRPMIC Ozone Monitoring Sites

Senior Center SiteHigh School Site

Red Mountain Site

Lehi Site

Reason for correcting raw data

• Ensures data is “actual data” when it is corrected to standard

• Regulatory program associate with standards• One of two agencies in EPA R9 adjusts data

from most recent calibration curve• Derived from QA Handbook Volume II• View it as Traceability of Standards• Standard is carried down to raw data

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-08-003. 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 certificationTransfer Standard Certification

Primary Standard Transfer Standard

Make: API 400E Make: TECO 49C-PS

S/N: 1900 S/N: 75056-378

Certified: 12-12-12

Date Slope Intercept Correlatation

12/1/09 1.0047 -0.1 1.00000

12/2/09 1.0039 -0.1 1.00000

12/3/09 1.0057 0.0 1.00000

12/4/09 1.0026 -0.2 1.00000

12/11/09 0.9939 0.0 1.00000

12/23/09 0.9982 -0.1 1.00000

4/19/10 0.9974 0.2 1.00000

6/25/10 0.9964 0.2 1.00000

10/18/10 0.9946 0.1 1.00000

3/3/11 0.9939 0.2 1.00000

9/26/11 0.9947 1.2 1.00000

2/10/12 1.0012 1.1 1.00000

10/8/12 1.0221 -1.7 1.00000

4/30/13 1.0213 -1.8 1.00000

AVG: 1.00463 -0.15000 1.00000

STDEV: 0.01348 1.31871 0.00000

AQP\AIR MONITORING\Data Records Management\Certification\Ozone\75056 TS\TS Slope Records

Average Slope and Intercept

Created slope & intercept from site monitor calibrationSalt River-Pima Maricopa Indian Community

MULTI-POINT CALIBRATION: OZONE

ANALYZER TRANSFER STANDARD Location: LehiMake/Model: API/400E Make/Model: TEII/49C-PS EPA Site ID: 04 013 7022

Serial No.: 1149 Serial No: 75056-378 Owner: SRPMIC/EPNR03 Meas: 4104 Bench Temp: 32.4 Date: 4/28/2013

03 Ref: 4104 Ozone Lamp Temp: 71.1 Time: 14:30Press: 27 Press: 727.6 Operator: MSlinkey

Samp Flow: 821 Flow Cell A: 0.634Samp Temp: 32.7 Flow Cell B: 0.634 DATA LOGGERPhoto Lamp: 58 Intensity Cell A: 110111 Make/Model: ESC/8832

Box Temp: Intensity Cell B: 109811 Serial No.:A3257KLast Cal Date: Mar 30, 2012 Slope: 1

Int: 0

CALIBRATION DATA (ppb)

INPUT OZONE: 0 35 90 180 400

STD. DAS STD. DAS STD. DAS STD. DAS STD. DAS

-1 0 35.8 34.4 90 88 181 180 403 400

-2 0 34.6 34.4 90 88 180 180 402 400

2 0 35.2 34.4 90 88 181 180 402 401

-1 0 35.5 34.3 90 88 180 179 403 401

2 0 35.6 34.2 90 87 180 178 400 401

-2 0 35.3 34.3 89 87 180 177 401 400

-1 0 35.7 34.2 89 87 179 176 402 401

-1 0 35.3 34.2 89 87 180 176 399 401

2 0 35.1 34.2 89 87 179 176 401 401

-1 0 34.9 34.2 90 87 180 176 400 401

STD AVG: 0 35 90 180 401

DAS AVG: 0 34 87 178 401

STD CORR AVG: 0 35 89 179 400

X Values 5 Y Values 5

(Slope) 1.003 (Intercept) -1.1 r: 0.99998

COMMENTS: Changed out Sintered Filter, Orifice, 2 O-rings and a new spring.Calibrate pressure sensor and flow checkedMulti-point calibrationEnabled @ 15:43

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 -0.0002) to calculate ambient data .0302 ppm and to determine the actual concentrations would be .0304 ppm

(.0302 - -0.0002)/ 1.001 = .0304 ppm

raw data – intercept

slope

EPA data reports are truncated

Sample of QC Data corrected to actualSalt River Pima-Maricopa Indian Community

OZONE: Level 1 & 2 Zero/Span And Precision Checks

Location: SC Date: June 12,2013 Operator: CSmithLogger Disable: 17:25 Logger Enable: 17:59

Analyzer Transfer StandardMake: Thermo Make/Model: TEII/49C-PModel: 49i Serial No: 75056-378

Serial No: CM10310069 Bench Temp: 35.6Bench Temp: 32 Lamp Temp: 56.5Bench Lamp: 54.3 03 Lamp Temp: 71.2

Pressure: 714.6 Pressure: 722.5Flow A: 0.690 Flow A: 0.631Flow B: 0.696 Flow B: 0.600

Intensity A: 76530 Intensity A: 107773Intensity B: 85561 Intensity B: 107028

03 Bkg/Coef: .0004/1.018 03 Bkg/Coef: -0.2/1.00Analyzer Slope: 1.003 Transfer Standard Slope: 1.00463

Analyzer Intercept: -0.0003 Transfer Standard Intercept: -0.00015

PRECISION and LEVEL 1 & 2 DATA RECORDS

.090 PPM Zero .400 PPMStandard DAS Standard DAS Standard DAS0.0900 0.0903 -0.0007 -0.0009 0.403 0.4080.0892 0.0908 -0.0007 -0.0004 0.403 0.4070.0895 0.0902 0.0009 -0.0008 0.402 0.4070.0898 0.0903 -0.0008 0.0006 0.401 0.4080.0899 0.0902 -0.0007 0.0003 0.401 0.4070.0898 0.0898 -0.0007 0.0009 0.402 0.4070.0894 0.0909 -0.0009 0.0005 0.401 0.4060.0898 0.0908 -0.0004 0.0002 0.401 0.4060.0901 0.0905 -0.0001 0.0004 0.400 0.4050.0895 0.0909 0.0009 -0.0007 0.400 0.4060.0897 0.0905 -0.0003 0.0000 0.4014 0.4067

ZERO/SPAN PRECISION

Corrected CorrectedRaw Data Data Raw Data Data

DAS Old Zero: 0.0000 DAS: 0.0905 0.0905DAS New Zero: 0.0000 0.000 STD: 0.0897 0.0894

XFER STD Zero: -0.0003 0.000DAS Old Span: 0.4067 Precision % Difference: 1.23

DAS New Span: 0.4067 0.4058 Span % Difference: 1.53XFER STD Span: 0.4014 0.3997 Zero % Difference: 0.00

Corrected Date=(DAS-Intercept)/Slope STD Data Corrected=(STD-Intercept)/Slope %Diff=(DAS-STD)/STD*100

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

Email: Stan.Belone@srpmic-nsn.gov • Mangas Slinkey, Senior Environmental Specialist

Email: Mangas.Slinkey@srpmic-nsn.gov• Shimmy Smith, Environmental Specialist

Email: Corwin.Smith@srpmic-nsn.gov

Administration• Chris Horan, Manager, Environmental Protection &

Natural Resources