The vapor pressure of Se and SeO2 measurement using thermogravimetric analysis

The vapor pressure data of Se and SeO 2 in low temperature range are essential for the study of emission and migration of selenium from stationary sources. The vapor pressure of SeO 2 at 353.2–473.2 K was measured by thermogravimetric analysis, and the corresponding pressure was 0.026–319.2 Pa. The vapor pressure of Se at 423.2–573.2 K was measured, and the corresponding pressure was 0.007–80.9 Pa. The triple point temperature and pressure of Se determined in this experiment were 491.2 ± 1 K and 2.16 ± 0.27 Pa. The extended uncertainty of temperature measurement ( k  = 2) was 1.86 K, and the extended relative uncertainty of pressure measurement ( k  = 2) was 0.128 p . The vapor pressures of Se and SeO 2 were fitted to Antonie equation, respectively, and compared with the available literature data.