Product Overview
The OHTS1031 is an online multi-parameter water quality monitoring sensor based on the fluorescence quenching principle, integrating dissolved oxygen (DO), pH, and temperature measurement functions. The sensor features an all-plastic enclosure structure and measures dissolved oxygen concentration by detecting the quenching effect of oxygen molecules on specific fluorescent materials.
Incorporating a built-in temperature compensation unit and pH electrode, the OHTS1031 is specifically designed for long-term underwater deployment scenarios. The communication interface utilizes RS485 bus with Modbus RTU protocol support, enabling multi-point networked monitoring for comprehensive water quality management systems.
Features
Triple Parameter Monitoring: Simultaneously measures dissolved oxygen concentration, pH levels, and water temperature with a single device, eliminating the need for multiple separate sensors and reducing installation costs.
Fluorescence Quenching Technology: Employs advanced optical measurement principles that eliminate electrolyte consumption and provide immunity to ion interference common in electrochemical sensors, significantly extending maintenance intervals.
Intelligent Compensation Algorithms: Automatically compensates for environmental variables including altitude up to 8848 meters and salinity up to 100 PSU, ensuring accurate dissolved oxygen readings across freshwater, brackish, and marine applications.
Modbus RTU Communication: Digital RS485 interface supports industry-standard Modbus RTU protocol with baud rate of 9600 bps and address range of 1 ~ 119, facilitating easy integration with PLCs, data loggers, and SCADA systems.
Multiple Operating Modes: Configurable for online continuous monitoring, portable handheld measurements, or specialized aquaculture pond mode that simplifies readings to mg/L concentration values only.
Comprehensive Calibration: Supports two-point dissolved oxygen calibration for zero and saturation points, plus three-point pH calibration using standard buffer solutions for maintained accuracy throughout the sensor lifecycle.
Robust Construction: All-plastic housing with stainless steel components provides waterproof protection to 10 meters depth, suitable for permanent submersion in aquaculture ponds, treatment tanks, and natural water bodies.
Applications
The OHTS1031 sensor is designed for diverse water quality monitoring applications including high-density aquaculture systems for fish, shrimp, and crab ponds where dissolved oxygen monitoring is critical for survival rates. It serves municipal and industrial wastewater treatment facilities for process monitoring and compliance reporting.
The sensor is equally suited for surface water and groundwater environmental monitoring stations, seawater and freshwater aquaculture operations requiring continuous parameter acquisition, and laboratory water quality analysis equipment integration. Additionally, it supports smart agriculture initiatives through irrigation water quality monitoring and integration with automated farm management systems.
Technical Specifications
| Parameter Category | Specification |
|---|---|
| Dissolved Oxygen Measurement | |
| Measurement Range | 0 ~ 20 mg/L (ppm) / 0 ~ 200 % Saturation |
| Measurement Accuracy | < 5 mg/L: ± 0.2 mg/L; ≥ 5 mg/L: ± 0.3 mg/L |
| Repeatability | 0.2 mg/L |
| Response Time | T90 < 60 s |
| Temperature Equilibration Recovery | < 0.1 mg/L drift recovery requires 300 s stabilization |
| Thermal Shock Recovery | < 0.1 mg/L drift recovery requires 2 hours stabilization |
| Temperature Measurement | |
| Measurement Range | 0 ~ 40 °C |
| Measurement Accuracy | ± 0.1 °C |
| Response Time | T80 < 600 s |
| pH Measurement | |
| Measurement Range | 4 ~ 11 |
| Measurement Accuracy | 0.1 |
| Electrical Characteristics | |
| Supply Voltage | 12V ~ 24V DC |
| Operating Current | 20 mA @ 12V |
| Environmental Adaptability | |
| Storage Temperature | -5 °C ~ 50 °C (humidity retention required) |
| Waterproof Depth | 10 m |
| Reliability and Lifetime | |
| Sensor Lifetime | Dissolved oxygen fluorescent membrane: 2 years; pH electrode: 1 year |
Physical Specifications
| Component | Material |
|---|---|
| Housing | ABS/PC, 304 Stainless Steel, 316 Stainless Steel |
| Pigtail Cable | TPU/PVC |
Note: Please refer to the product outline drawing for specific dimensions.
FAQ
Q: How should I maintain the fluorescent sensing membrane?
A: Keep the measurement sensing membrane clean and intact at all times. If the membrane surface becomes contaminated, gently wipe it with a soft cloth and clean water only. Do not use benzene or alcohol-based solvents for cleaning. Never scrape or scratch the membrane surface as this will permanently damage the sensor.
Q: What is the proper calibration procedure for dissolved oxygen?
A: When performing two-point calibration, you must calibrate the zero oxygen point first, then the saturated oxygen point. For saturated oxygen calibration, tap water aerated for more than 1 hour reaches approximately 100 percent saturation and can serve as a reliable reference. pH calibration requires stabilization in standard solution for more than 1 minute at each point.
Q: What are the electrical installation safety requirements?
A: During installation, ensure the sensor connector does not immerse in water. The waterproof connector must remain above water level as much as possible to prevent prolonged immersion. Connect power and RS485 bus through the waterproof connector ensuring proper polarity.
Q: How long should the sensor be immersed before first use?
A: For long-term online measurement applications, the sensor must be immersed for at least 1 hour during first use to allow adequate hydration of the fluorescent membrane. Accurate measurement data can only be obtained after this stabilization period.
Q: What are the storage requirements for long-term storage?
A: Store the sensor at temperatures between -5 degrees Celsius and 50 degrees Celsius. The fluorescent membrane must be kept moist during storage to prevent drying out. Humidity retention is required to maintain sensor performance and extend membrane lifetime.