The substance fraction of atomized component in the component consumed. The efficiency of atomization is measured in a given part of the flame, usually the observation space; \(\varepsilon_{\rm{a}} = \varepsilon_{\rm{n}}\ \chi _{\rm{s}}\ \chi _{\rm{v}}\ \chi _{\rm{a}}\). The signal is a function of the product \(q_{\rm{v}}\ \varepsilon_{\rm{a}}\), but \(\varepsilon_{\rm{a}}\) is also a function of \(q_{\rm{v}}\), usually decreasing at high volume rates.