Instruction Manual for Met One models including: 36, 37, 38, C-12 Portable Black Carbon Monitor, C-12, Portable Black Carbon Monitor, Black Carbon Monitor, Carbon Monitor, Monitor

Title

Henry Hogo

Field Evaluation MetOne C12

pirms 1 dienas — 880 and 950 nm; instrument user manual says BC is defined by absorption at 880 nm. ➢Cost: ~$32,000. ➢Time resolution: 1-min. Magee Scientific AE33. MetOne C12 ...

20 hours ago — 880 and 950 nm; instrument user manual says BC is defined by absorption at 880 nm. ➢Cost: ~$32,000. ➢Time resolution: 1-min. Magee Scientific AE33. MetOne C12 ...

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metone-c12---field-evaluation
Field Evaluation Met One C-12

Background
· From 6/21/2024 to 8/21/2024, three Met One C-12 units were deployed at the South Coast AQMD Long Beach Route 710 Near Road ambient monitoring site and were run side-by-side with Best Available Technology (BAT) instruments measuring the same pollutants.

· Met One C-12 (3 units tested):

· South Coast AQMD Reference instruments:

 Light Absorption

· Magee Scientific AE33:

 Each unit measures: Black Carbon (BC) in ng/m3

 Light Absorption

 Output provided at 370 and 880nm, only 880nm data  Measures black carbon (BC) in ng/m3

is analyzed

 Output provided at 370, 470, 520, 590, 660,

 Unit cost: ~$3,000

880 and 950 nm; instrument user manual

 Time resolution: 1 minute  Units IDs: 36, 37, and 38

says BC is defined by absorption at 880 nm  Cost: ~$32,000  Time resolution: 1-min

Met One C-12

Magee Scientific AE33
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Data validation & recovery
· Basic QA/QC procedures were used to validate the collected data (i.e. obvious outliers, negative values and invalid data-points were eliminated from the data-set)
· Data recovery from Unit 36, Unit 37 and Unit 38 was ~98.2%, ~98.1% and ~98.2%, respectively for all PM measurements
Met One C-12; intra-model variability
· Absolute intra-model variability was ~15.03 ng/m3 for BC measurements (calculated as the standard deviation of the three sensor means)
· Relative intra-model variability was ~2.54% for BC measurements (calculated as the absolute intra-model variability relative to the mean of the three sensor means)
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Met One C-12 vs Magee Scientific AE33 (BC; 5-min mean)
· The Met One C-12 sensors showed moderate to strong correlations with the corresponding Magee Scientific AE33 data (0.66 < R2 < 0.76)
· Overall, the Met One C-12 sensors underestimated the BC mass concentrations as measured by Magee Scientific AE33
· The Met One C-12 sensors seemed to track the BC diurnal variations as recorded by Magee Scientific AE33
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Met One C-12 vs Magee Scientific AE33 (BC; 1-hr mean)
· The Met One C-12 sensors showed strong correlations with the corresponding Magee Scientific AE33 data (0.84 < R2 < 0.85)
· Overall, the Met One C-12 sensors underestimated the BC mass concentrations as measured by Magee Scientific AE33
· The Met One C-12 sensors seemed to track the BC diurnal variations as recorded by Magee Scientific AE33
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Met One C-12 vs Magee Scientific AE33 (BC; 24-hr mean)
· The Met One C-12 sensors showed very strong correlations with the corresponding Magee Scientific AE33 data (0.93 < R2 < 0.95)
· Overall, the Met One C-12 sensors underestimated the BC mass concentrations as measured by Magee Scientific AE33
· The Met One C-12 sensors seemed to track the BC daily variations as recorded by Magee Scientific AE33
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Summary: Black Carbon

Average of 3

Sensors, BC

Average SD (ng/m3) (ng/m3)

R2

Met One C-12 vs Magee Scientific AE33, BC

Slope

Intercept

MBE1 (ng/m3)

MAE2 (ng/m3)

RMSE3 (ng/m3)

5-min 599.8 717.3 0.66 to 0.75 0.88 to 0.97 83.5 to 165.2 -104.2 to -75.0 103.3 to 127.7 246.3 to 298.2

Magee Scientific AE33 (BC, ng/m3)

Ref. Average
688.5

Ref. SD

Range during the field evaluation

477.7

41.4 to 15183.1

1-hr 602.0 375.4 0.84 to 0.85 0.91 to 0.99 104.4 to 128.5 -98.5 to ­67.0 84.4 to 109.8 168.8 to 182.8 693.4

385.7

92.4 to 5987.7

24-hr 604.0 200.3 0.94 1.05 to 1.10 39.6 to 44.2 -101.8 to -70.1 72.1 to 101.8 88.8 to 116.7 702.1

225.2

226.9 to 1377.2

1 Mean Bias Error (MBE): the difference between the sensors and the reference instruments. MBE indicates the tendency of the sensors to underestimate (negative MBE values) or overestimate (positive MBE values). 2 Mean Absolute Error (MAE): the absolute difference between the sensors and the reference instruments. The larger MAE values, the higher measurement errors as compared to the reference instruments. 3 Root Mean Square Error (RMSE): another metric to calculate measurement errors.

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Discussion
· The three Met One C-12 sensors' average data recovery was ~98.2%. · The absolute intra-model variability for the Met One C-12 sensors was ~15.03 ng/m3 · The Met One C-12 sensors showed strong correlations with the corresponding reference data (0.84 < R2 <
0.85, 1-hr mean). The sensors underestimated the BC mass concentrations as measured by Magee Scientific AE33 instrument. · No sensor calibration was performed by South Coast AQMD staff for this evaluation. · Laboratory chamber testing is necessary to fully evaluate the performance of these sensors under controlled T and RH conditions, and known target and interferent pollutants concentrations.
· These results are still preliminary
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