The vapor pressures of solid and liquid ozone

Vapor pressures of solid and liquid ozone have been measured over a temperature range 87 to below 66 K. The experiment was performed under flow conditions, the gas was analyzed by a precision mass spectrometer system. In the range of solid ozone two forms, supercooled and crystalline ozone, were found. A least square fit of the data for crystalline ozone resulted in the equation log P(Torr)=A+B/T where A=10.460 and B=−1021.6. The estimated uncertainty of the data is ±1.0%. A triple point temperature of 79.6±0.3 K was found where supercooled and crystalline ozone data intersect.