The Data Supplement, presented in two volumes, documents data in greater detail than was practical in the final reports for this contract. It provides details to researchers interested in performing their own analyses. Readers are referred to the contract final reports for information on objectives, selection of units, measurement procedures, interpretations, and conclusions. Data for gaseous emission concentrations of NO, NOx, CO, HC, SO2, and SO3 are in parts per million by volume (ppm) on a dry basis corrected to 3 percent O2 by volume (dry) in the flue gas. Data in this volume are arranged by Location No. for Locations 1 and 7. A location is defined as one company or plant in which one or more units were tested. Each unit tested at a location is identified by a Unit No. The contract final reports refer to test numbers when data are discussed. Test numbers are of the form xx/yy-zz, where xx = Location No., yy = Test Series No. (e.g., oxygen variations, load variations, register adjustments), and zz = Test No. in that series.