A system and method for removing cross-talk in measured forces between a railway wheel set and the railhead of underlying track such as found in angle of attack measurements for shallow curvature track. The system can upload media content to a generator that produces a digital certificate that includes a short identifier associated with the content. A further aspect uses spectral amplitude modulation to isolate spectral bands by scanning one or more transmission slits or openings, and measuring andor calculating the first derivative of a phase across an entire spectrum. The at least one sidewall may have an integrally formed liquid passageway therein having an upper opening coupled in fluid communication with the spray head tube, and may have a lower liquid pick-up opening adjacent the base.