This part of ISO 14934 describes three methods for calibration of total hemispherical radiometers and total
heat flux meters that are exposed to a well-defined radiation from a radiant heat source. The equipment is
designed to minimize influences due to convective heat transfer during calibration. It is important to note that
when the instruments are used in practice they measure a combination of radiant and convective heat
transfers. The latter will depend on the design of the heat flux meter, the orientation, local temperature and
flow conditions, and on the temperature of the cooling water.