Figure 4.

Germicidal efficacy achieved by our fabricated far‐ultraviolet C (UVC) devices. A pure culture of E. coli was used to investigate the germicidal efficacy. a) Control plate (0 mJ cm⁻² dose). b) Plate disinfected with a 4.0 mJ cm⁻² dose. c) Plate disinfected with an 8.0 mJ cm⁻² dose. d) Plate disinfected with a 12.0 mJ cm⁻² dose. e) Log‐reduction behavior (normal log) as a function of the dose. The inactivation rate constant can be fitted by the slope of the log‐reduction behavior, which results in a value of κ = 0.58 cm² mJ⁻¹.