TOMO, Haryo Satriyo; KHANAFIAH, Deni. An Optical Technology–Based Approach for Emission Opacity Monitoring Derived from the Ringelmann Chart. Jurnal Teknik Lingkungan, [S. l.], v. 30, n. 2, p. 1–8, 2024. DOI: 10.5614/j.tl.2024.30.2.1 . Disponível em: https://envengjournal.com/index.php/jtl/article/view/305. Acesso em: 30 apr. 2026.