Assessing the progress of the performance of continuous monitoring solutions under single-blind controlled testing protocol

08 February 2024, Version 2
This content is a preprint and has not undergone peer review at the time of posting.


Recent regulatory spotlight on continuous monitoring (CM) solutions and the rapid development of CM solutions has demanded the characterization of solutions performance through regular, rigorous testing using consensus test protocols. This study is the second known implementation of such protocol involving single-blind controlled testing of 9 CM solutions. Controlled releases of rates (6 to 7100) g CH4/h over durations (0.4 to 10.2) hours under wind speed range of (0.7 to 9.9) m/s were conducted for 11 weeks. Results showed that 4 solutions achieved method detection limits (DL90s) within tested emission rate range with all 4 solutions having both the lowest DL90s (3.9 [3.0, 5.5] kg CH4/h to 6.2 [3.7, 16.7] kg CH4/h) and false positive rates (6.9% to 13.2%) indicating efforts at balancing low sensitivity with low false positive rate. Quantification results showed wide individual estimate uncertainties with emissions underestimation and overestimation by factors up to > 14 and 42 respectively. Three solutions had > 80% of their estimates within a quantification factor of 3 for controlled releases in the ranges of (0.1 – 1] kg CH4/h and >1 kg CH4/h. Relative to the study by Bell et al., current solutions performance, as a group, generally improved primarily due to solutions from the study by Bell et al. that retested. This result highlights the importance of regular, quality testing to the advancement of CM solutions for effective emissions mitigation.


emissions mitigation
detection limit
emissions quantification
source attribution
natural gas

Supplementary materials

Supporting Information
The zipped file contains the supporting document (PDF) along with some folders. Each folder contains the blinded performance report and data of each continuous emissions monitoring technology that participated in the study. In detail, the folder contains a report "CMReport" (PDF), controlled release data file "testCenterControlledReleases" (csv), data of paired controlled release with detection reports "classifiedData" (csv), and data column header description "OutputHeaderDescriptions" (csv).


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