A system that determines an amount of toner mass present on a toner application surface, and comprises a specular reflection sensor, a diffuse reflection sensor, an output combination module, and a mass determination module. The specular reflection sensor receives electromagnetic radiation that has been specularly reflected by the toner application surface, and generates a specular reflection output representative of the received electromagnetic radiation. The diffuse reflection sensor receives electromagnetic radiation that has been diffusely reflected by the toner application surface, and generates a diffuse reflection output representative of the received electromagnetic radiation. The output combination module creates a combined output by combining the specular reflection output and the diffuse reflection output with the purpose of reducing a noise source common to both specular and diffuse outputs to improve the signal to noise ratio. The mass determination module determines an amount of toner mass present on the toner application surface based on the combined output.