A 61 cm long rapid quench vessel of new design has been calibrated for internal temperature gradients at elevated temperature and pressure with a water pressure medium. Calibrations were done over 6.8 cm of the hot end of the vessel at angles of inclination (measured from the horizontal) of −10°, −5°, −2.5°, 0°, +2.5°, +5°, and +10° at temperatures of 300, 450, 600, and 750°C and 2 kbar = Ptot. Results show a water pressure medium is satisfactory at all temperatures if the hot end is raised +5°.
A similar set of measurements were performed on a standard 30.5 cm vessel with a filler rod. The results show the temperature gradient to be essentially inclination independent from −10° to +10° although the temperature correction is inclination dependent.