When selecting a level indicator, you must prioritize material compatibility and pressure ratings. For corrosive environments, ensure the wetted parts are made of 316L Stainless Steel, PTFE, or PP. The device must be rated for the maximum operating pressure and temperature of the tank; for example, high-pressure boilers require reflex or transparent glass gauges with a rating of at least PN40 or higher. Additionally, verify the measurement accuracy, typically looking for a margin of error within ±5mm or 0.5% of the full scale.