When sourcing capacitive level sensors, you must prioritize dielectric constant compatibility, as the sensor's accuracy depends on the material being measured. Ensure the device features sensitivity adjustment to calibrate for different media (liquids, solids, or powders). Key hardware specs include IP67 or IP68 ingress protection for moisture resistance and stainless steel (316L) or PTFE probes for chemical compatibility. For high-precision needs, look for sensors with active shield technology to ignore material buildup or 'clinging' on the probe.