§ 145.142. Definitions.

 The following words and terms, when used in this subchapter, have the following meanings, unless the context clearly indicates otherwise:

   CEMS—Continuous Emission Monitoring System—The equipment required under this subchapter or Chapter 139 (relating to sampling and testing) to sample, analyze, measure and provide, by readings taken at least every 15 minutes of the measured parameters, a permanent record of NO_x emissions.

   Clinker—The product of a Portland cement kiln from which finished cement is manufactured by milling and grinding.

   Portland cement—A hydraulic cement produced by pulverizing clinker consisting essentially of hydraulic calcium silicates, usually containing one or more of the forms of calcium sulfate as an interground addition.

   Portland cement kiln—A system, including any solid, gaseous or liquid fuel combustion equipment, used to calcine and fuse raw materials, including limestone and clay, to produce Portland cement clinker.