Development of a Tunable Diode Laser Absorption Spectroscopy System for Quantification of Transient Emissions from Liquid Hydrocarbon Storage Tanks
Bibliographic record
Abstract
Fixed-roof atmospheric storage tanks are used throughout the oil and gas sector to store liquid hydrocarbons and are a key source of volatile organic compound (VOC) emissions.Despite their prevalence, vented emissions from these tanks are rarely monitored and remain poorly understood.This thesis presents a non-intrusive, inline optical measurement system to quantify oxygen fraction (which can be used to infer VOC fraction) in the vent line of an uncontrolled tank.The sensor utilizes tunable diode laser absorption spectroscopy with wavelength modulation to target near infrared absorption bands of diatomic oxygen ingested into the tanks during diurnal tank breathing processes and is compact, robust, and compliant with CSA zoning standards.Lab characterizations of two variants of the system are presented.Over the full-scale (0 -20.95% O2) measurement range, the optical variant had a long-term precision of < 0.72% absolute (at 95% confidence) while the detector variant improved this to < 0.31% absolute.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.000 |
| 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".