For sewage treatment gates, position feedback must stay stable under moisture, sludge, vibration, and frequent washing. A waterproof magnetostrictive displacement sensor converts gate opening into a precise electrical signal for PLC and SCADA control. Typical technical parameters include measuring ranges from 50 mm to 5000 mm, resolution up to 0.01 mm, linearity within +/-0.05% FS, and repeatability within +/-0.01% FS. Output options cover 4-20 mA, 0-10 V, RS485/Modbus, and SSI. The sensor usually operates on 24 VDC with wide voltage tolerance and low power consumption. For sewage environments, the enclosure should meet IP67 or IP68, with a stainless steel or corrosion-resistant probe and a pressure-resistant sealed cable. Working temperature is commonly -40 C to +85 C, while the housing must resist humidity, condensation, and chemical splash. Strong EMC protection, reverse-polarity protection, and surge protection improve reliability. Insulation resistance should exceed 100 MOhm at 500 VDC, and cable length can be customized for site wiring. Response time is typically under 1 ms, and stroke speed can reach 10 m/s. Installation should keep the sensor aligned with the gate stroke, avoid side load, use a stable bracket, and allow easy maintenance. The probe material should resist sludge abrasion, and the connector must remain sealed after maintenance. A waterproof magnetostrictive displacement sensor thus provides long-term, accurate gate position monitoring for wastewater treatment plants.