A printing device is provided, wherein the printing device is configured to print a printing fluid onto a printing medium. The printing device includes a printing fluid reservoir configured to hold a volume of the printing fluid, a print head assembly configured to transfer the printing fluid to the printing medium, wherein the print head assembly is fluidically connected to the printing fluid reservoir, and a printing fluid detector configured to detect a characteristic of the printing fluid. The printing fluid detector includes a first electrode and a second electrode configured to be in contact with the printing fluid, wherein at least one of the first electrode and the second electrode includes an electrically conductive coating disposed over an electrically conductive substrate.