<p>Delhi’s air pollution remains a persistent atmospheric and public-health challenge, driven by diverse emission sources, extensive secondary aerosol formation, and unfavourable meteorological conditions of the Indo-Gangetic basin. A fundamental limitation in effective air-quality governance has been the absence of a nationally harmonised measurement ecosystem that ensures metrological traceability, quantified uncertainty, and long-term comparability of air-quality data across monitoring networks. This paper places environmental metrology at the centre of air-pollution management and adopts the Aswal Model as an organising scientific framework that explicitly links measurement capability, diagnostic understanding, and accountable mitigation. The framework is operationalised through the India Certification Scheme for Environmental Monitoring Instruments (NPLI-CS) of CSIR–National Physical Laboratory, which embeds traceability, performance verification, and uncertainty evaluation into both continuous emission and ambient air-quality monitoring systems. Building on this metrological foundation, the paper presents a measurement-anchored diagnosis of Delhi’s pollution sources, encompassing combustion emissions, mechanically generated and re-suspended dust, construction activities, open waste and agricultural residue burning, and secondary aerosol chemistry. These diagnostics are translated into Scientific Remediation Measures (SRMs) formulated as testable interventions whose effectiveness can be quantitatively evaluated using certified measurement systems, consistent with the Aswal Model’s emphasis on evidence-based governance. The analysis demonstrates that sustained improvement in Delhi’s air quality requires a metrology-anchored pathway in which measurement credibility, scientific diagnosis, and mitigation outcomes remain continuously aligned through a feedback-driven governance framework.</p>