The Surface Heat Budget of the Arctic (SHEBA) is a one-year study that involves, among other things, the careful measurement of all components of the surface energy budget at a site on the Arctic icecap. The longwave (thermal) radiative flux component is measured with standard precision infrared (PIR) hemispherical flux radiometers manufactured by Eppley Laboratories. In this paper we will present an intercomparison of PIR data obtained by the SHEBA Surface Flux Group (SSFG), the SHEBA Project Office (SPO), the Department of Energy Atmospheric Radiation Measurement (ARM) program, and the NCAR Portable Automated Mesonet (PAM) team. All PIR units were calibrated at the Climate Monitoring and Diagnostics Laboratory (CMDL) in Boulder prior to the experiment. Data from November 1 1997 to January 8 1998 will be used. Our analysis will include an investigation of the errors caused by rime ice coatings on the PIR domes and the absolute instrument differences in ideal (clean) conditions. Logging methods, attempts to keep the domes ice free using fans and heaters, factory versus CMDL calibrations, and absolute accuracy will also be discussed