Test with 3x6 chamber and 12 gram cylinder in bicycle tire fill adapter:
Initial pressure rose to 80 psi.
Waited approx 30 seconds, rose to 85 psi.
Started blowing gently (warm air) across the cylinder.
Waited another minute, got to 91 psi.
Waited another few minutes (now no ice on the cylinder, so no dry ice inside, pressure rose to enough to trigger the overpressure valve at 100 psi, estimate it would have made approx 103 psi.