A two-in-one temperature and pressure gauge is constituted primarily by a shell, a housing, a score panel, a needle set, a temperature sensing mechanism, and a pressure sensing mechanism. A first light source generates a first single wavelength signal serving as a continuous light having a first wavelength \u03bb1 as a wavelength of a carrier wave. A titanium dioxide pigment for plastics resin compositions, characterized in that each titanium dioxide particle has a dense hydrous silica coat covering its surface and an organic compound coat formed on the silica coat not through an interlayer. A slot couples the hole and the upper edge. The method can avoid the scratch issue of wafer surface by particles resulting from pH shock and cross contamination. The image-processing method is thus performed with the color matching process result taken into account.