1. In the following paragraphs of this Part of this Schedule– “input temperature” means the temperature of the milk immediately before the application of the steam; “operational change” means any change in the site, layout or construction of equipment for treating milk by the ultra high temperature method by the direct application of steam, or any change in the steam supply or in the particular temperature used for treating the milk as aforesaid; “output temperature” means the temperature of the vapour or of the milk in either case at the point of leaving the evaporative cooling expansion vessel.