<prompt> Pressure of Nitrous oxide cylinder at 100 and 40 volume respectively measured by pressure gauge is:750 Psi and 500 Psi750 Psi and 750 Psi750 Psi and 375 Psi750 Psi and 275 Psi  <response>: In cases of gases which are in liquid form in cylinder N2O , pressure gauze shows always full till it becomes Zero Thus in case of N2O , whether cylinder has 100 or 40 volume , pressure gauze will always show 750 Psi. 