The DB1 Liquid Level System requires a compressed gas supply. The most common gas is a 225 ft3 nitrogen bottle with an appropriate "automatic pressure relieved" pressure regulator. The pressure range set on the regulator depends on the water level to be recorded. For example, if the DB1 system is installed in a stilling well to measure stream level, and the stream level fluctuates between 5 and 15 ft (2.2 and 6.5 psi), set the pressure regulator above 7 psi (read 10 psi) to ensure adequate press