Carbon dioxide emissions made up from fossil fuel is a weighted contribution to the total carbon dioxide emissions in Korea. To keep on track of the long-term mitigation pathway, the new solution for enhancing the emission flow measurements more accurately in industrial smokestacks is urgent. Thus, along with the popular instrument, an S-type pitot tube, three-dimensional (3D) pitot tubes have been introduced to determine the emission flow in smokestacks by international standards and Korean regulations. To comply with the regulations mandated in Korea, the Korea Research Institute of Standards and Science established the 3D pitot tube calibration system for stack flow measurements assembled to the airspeed standard system. This calibration system can produce accurate pitch and velocity calibration curves for 3D pitot tubes in the range of testing pitch angle within±30, and have an expanded uncertainty attributed to the calibration curves (0.005–0.086) and (1.3–2.9)% for the prism pitot tube and (0.008–0.175) and (1.6–3.1)% for the spherical pitot tube.