This is a post from PSN posted by Eric...
"1.0volt@580psi, 3.22volts@2520psi
(PSI) (MPA) Voltage
0 0 .02v
200 1.5 .4v
400 3 0.73v
600 4 .96v
800 5.5 1.2v
1000 7 1.4v
1200 8 1.6v
1400 9.7 1.9v
1600 11 2.1v
1800 12.4 2.3v
2000 13.8 2.6v
2200 15.2 2.8v
2400 16.5 3v
2600 18 3.3v
2800 19.3 3.5v
3000 20.6 3.8v
You can follow the trend to 4000psi."