Calibration of a fugitive emission rate measurement of an area source
Bibliographic record
Abstract
A major challenge to measuring fugitive emission rates from large area sources, such as landfills or tailings ponds, has been the establishment of the accuracy of such methods, or of a particular measurement. When such measurements are carried out, they are invariably associated with a relatively high degree of uncertainty. The Airborne Matter Mapping (AMM) method is a new method of measuring fugitive emission rates that can be applied to large area sources. The method was applied to the measurement of methane emissions from a landfill to assess the potential accuracy of the method, and the measurement process was calibrated to increase confidence in the measured value. First, a measured rate of methane from a gas cylinder was released from near the center of the landfill and the AMM method was applied to measure the methane flow rate across a measurement surface. Then, the AMM method was performed a second time along the same measurement surface without the intentional release of methane. The difference of the flow rates across the measurement surface were then compared with the measured rate of methane released from the gas cylinder. The relatively small difference of –5.7% between the flow rates, relative to the methane release rate from the gas cylinder, provides confidence in the accuracy of this AMM method measurement. An adjustment to the AMM method analysis was made such that the difference between the flow rates was negligible, which resulted in a calibrated measurement of the methane emission rate from the landfill of 0.87 g/sec. Implications: To properly manage fugitive emissions to the atmosphere, accurate measurement of fugitive emission rates is necessary. The Airborne Matter Mapping (AMM) method has the potential to provide accurate measurements of fugitive emission rates from large area sources, such as landfills, tailings ponds, and mines. The measurements can be calibrated against the metered release of a standard. This calibration can provide confidence in the accuracy of an AMM method measurement of the fugitive emission rate from a source.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.007 | 0.012 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".