q: did you hear oxygen went on a sorry for the bad chemistry · 2 q: did you hear oxygen went on a...
TRANSCRIPT
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Q: Did you hear oxygen went on a date with potassium?
Sorry for the bad chemistry jokes…all the good ones Argon.
A: It went OK.
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Infographic Following our data point...
Learning Objectives
• Know the types of calibrations • Know when and how to calibrate an analyzer or
sampler • How to document calibration • Focusing on Ozone and PM 2.5
We know about calibrations, but standardization for quality control is IMPORTANT!
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What does it mean to calibrate?
• Aligning or checking the output of an instrument to a known “true” standard.
• Ensure quality of data across monitoring network.
• Required in Code of Federal Regulations – Title 40, Part 50
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Types of Calibrations
• AS-IS – Performed initially to
assess the instruments accuracy
– Verifies the accuracy of the recently generated data (usually back to previous calibration)
– Performed to determine if the instrument warrants further maintenance
• FINAL – Performed after an
instrument has been aligned to a “true” standard
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OMG! When do I calibrate???
TO ENSURE QUALITY OF DATA, instruments must be calibrated: • During initial field installation • Following physical relocation • After any major maintenance or repair • After an instrument has drifted outside of
acceptable quality control limits • Bi-annually (every 6 months)
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OMG! When do I calibrate???
If possible, routine instrument calibrations should be conducted in the spring and fall months. Thus instrument calibrations bracket the beginning and end of high ozone season.
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How do we do these calibrations you speak of?
• Be performed in a consistent manner so that all network monitoring stations in all areas of the State are calibrated in a similar fashion.
• Done in accordance with appropriate CARB PQAO SOP and/or instrument manual.
• Performed by staff other then station operator – INDEPENDENT!
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Multipoint Calibrations Instruments are challenged at a minimum of four different gas concentrations in addition to a pre and post zero check. • High calibration point at approximately 80%
of full scale of instrument range. • Low calibration point should meet
requirements of 40 CFR Part 58 Appendix A, Section 3.2 – 0.01 – 0.10 PPM
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Multipoint Calibrations Cont. To meet those criteria our typical calibration points are: 0, 320, 160, 70, 50, 0 parts per billion.
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Ozone Calibrations
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• AS-IS calibrations should me made prior to making any analyzer repairs or adjustments.
• Ozone scrubber and solenoid valve should not be replaced without first performing an AS-IS calibration.
Get that analyzer in line!
Adjust slope and intercept of analyzer to true standard. • If overall percent
accuracy is: – + or – 3% overall – > 3 PPB for the low
point • If ozone scrubber is
replaced
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14 y = 0.8607x + 0.0005
0.0
0.1
0.2
0.3
0.4
0.5
0.0 0.1 0.2 0.3 0.4 0.5
Inst
rum
ent R
espo
nse
- Ozo
ne (p
pm)
True Ozone Concentration (ppm)
Ozone Calibration Graph - As Is
Station: 99-999 Sampler Prop. # : 20060144 Calibration Date: 10/01/14 Created By: Cali Brator API 400
Pollutant: Ozone
15 y = 0.9985x - 0.0015
0.0
0.1
0.2
0.3
0.4
0.5
0.0 0.1 0.2 0.3 0.4 0.5
Inst
rum
ent R
espo
nse
- Ozo
ne (p
pm)
True Ozone Concentration (ppm)
Ozone Calibration Graph - Final
API 400 Pollutant: Ozone
Station: 99-999 Sampler Prop. # : 20060144 Calibration Date: 10/01/14 Created By: Cali Brator
FINALize • Final calibration to verify adjustment.
• Keep record of previous slope/intercept;
in case problems found with standard.
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For IZS…O3 Gen Cal
• Aligns slope/intercept of photometer to slope/intercept of ozone generator.
• Should be performed: –Following a change or rebuild of
sample pump –Adjustment of flow rate –Replacement of ozone lamp –After conducting a final calibration
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For IZS…O3 Gen Cal
After O3 Gen Cal, record average of next three auto IZS calibration sequences to determine new expected values for zero, precision, and span for quality control purposes.
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Calibration Report Include: • Analyzer and Site ID • Diagnostics and correction
factors of transfer standard, flow standard, and analyzer
• Slope and intercept • Calibration points with
response from transfer standard and analyzer
• Percent difference from true
Per TSA, reports to be housed electronically on server and copy at monitoring station.
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Q: Why do chemists like nitrates so much?
A: They’re cheaper then day rates.
Continuous Sampler (BAM) Calibrations • Calibration includes
verifying and calibrating of: – Outside temperature
sensor – Internal pressure
sensor – Volumetric flow
controller • Including leak check
• Verify each with certified standard; BGI Delta Cal
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When should I adjust???
• Temperature – + or – 2.0 degrees Celsius from true
• Pressure – >10 mmHG from true • Flow – more then + or – 2% from true
– If leak check does not drop below 0.5 LPM, further troubleshooting needed
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Calibration Report Include: • Analyzer and Site ID • Diagnostics and correction
factors of pressure, flow, and standard
• Slope and intercept • Calibration points with
response from transfer standard and sampler
• Percent difference from true
Per TSA, reports to be housed electronically on server and copy at monitoring station.
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Are we done yet?
• We know the types of calibrations • We know when and how to calibrate an
analyzer or sampler • We know how to document calibrations
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