When sourcing sewage level sensors, you must prioritize material compatibility and measurement technology. For corrosive environments, ensure the sensor body is made of 316L stainless steel, PTFE, or PVDF to prevent chemical erosion. The two most reliable technologies are Submersible Hydrostatic Pressure sensors (cost-effective for deep wells) and Ultrasonic/Radar Non-contact sensors (ideal for high-solids or foaming liquids to avoid clogging). Ensure the device supports standard industrial outputs like 4-20mA, RS485 (Modbus-RTU), or 0-10V for seamless integration with PLC systems.