Seeed Studio S-YW-01B | Industrial RS485 Modbus-RTU Liquid Level Sensor

The Seeed Studio S-YW-01B is an industrial-grade submersible liquid level sensor measuring liquid height across a 0 to 5-metre range and transmitting data via the RS485 Modbus-RTU protocol. Built around a high-sensitivity silicon piezoresistive sensing core with a 304 stainless steel shell and 316L stainless steel wetted core, it is engineered for continuous immersion in water, edible oil, and other mildly corrosive liquids. The sensor is IP68-rated and includes a 5.3-metre waterproof cable with an aviation-style connector, making it suitable for deployment in reservoirs, tanks, deep wells, pump stations, and wastewater treatment facilities. It connects directly to any device supporting Modbus-RTU over RS485 — including PLCs, data loggers, recorders, inverters, and SCADA systems — with no proprietary gateway required.

Core Capabilities

High-Accuracy Piezoresistive Sensing Silicon piezoresistive core delivers ±0.25% F.S. accuracy with a 5 ms response time (≤90% F.S.) and a zero temperature drift of ±0.03% F.S./°C, ensuring reliable measurement in fluctuating temperature environments from −10°C to +70°C. 316L Stainless Steel & IP68 Construction 304 stainless steel outer shell with 316L stainless steel wetted core and special rubber-insulated cable rated from −40°C to +85°C. Anti-corrosion material and anti-blocking design ensure reliable long-term operation in submersed, outdoor, and chemically aggressive environments. Universal RS485 Modbus-RTU Connectivity Outputs measurement data over RS485 using the Modbus-RTU protocol (Slave address: 0x1A, default baud rate: 9600 bps). Compatible with PLCs, SCADA systems, data loggers, recorders, and inverters. Supports baud rates from 1200 to 115200 bps and a multi-unit output selection including m, cm, mm, Pa, KPa, PSI, mH2O, and more. 200% Overload Capacity & Long-Term Stability Rated for 200% F.S. overload capacity with a long-term stability of ≤0.2% F.S./year, ensuring reliable performance in surge conditions such as pump stations and flash flood monitoring without permanent damage to the sensing element.

Industrial Applications

• Reservoir & Tank Level Monitoring: Continuously measure liquid height in storage tanks, reservoirs, and holding vessels containing water, edible oil, or mildly corrosive liquids, with RS485 data readable directly by SCADA or PLC control systems. • Pump Station & Deep Well Monitoring: Deploy in pump wet wells, high pool pump stations, and deep wells to automate pump control based on real-time level data, preventing dry-running and overflow conditions. • Wastewater Treatment: Monitor level in wastewater collection pits, equalisation tanks, and treatment basins. The 316L stainless steel wetted core and anti-blocking probe design maintain accuracy in solids-laden or chemically active liquids. • River, Marine & Dammed Lake Monitoring: Suitable for environmental hydrological monitoring in rivers, marine monitoring stations, and dammed lake systems, where submersion, high-vibration, and impact resistance are required for uninterrupted operation.

Technical Integration

The S-YW-01B communicates via RS485 Modbus-RTU (Function Codes 0x03 Read / 0x06 Write) with a default slave address of 0x1A and baud rate of 9600 bps (configurable from 1200 to 115200 bps). The wiring connector follows a 4-wire colour-coded scheme: Red (VCC+), Green (VCC−), Blue (RS485-A), Yellow (RS485-B), with an additional red air pipe for atmospheric reference. The sensor is also compatible with the Seeed SenseCAP Sensor Hub 4G Data Logger for cellular IoT deployments requiring seamless cloud data management. Power supply range is 11–30V DC. For integration support, PLC configuration templates, or system design assistance, contact the ShopIoT technical team.

Certifications

CE FCC RoHS