Overview: Engineering Value of Suspended Solids (TSS) Monitoring in Industrial Scenarios

In municipal wastewater treatment, industrial wastewater discharge, and surface water environmental monitoring, Total Suspended Solids (TSS) is a core physicochemical indicator for assessing water pollution levels. Suspended solids not only directly affect water turbidity and transparency but may also adsorb heavy metals, organic pollutants, and pathogenic microorganisms, leading to water quality deterioration. For system integrators (SI), building a high-precision, automated online suspended solids monitoring system that requires minimal human intervention is key to enhancing the intelligence of water treatment processes.

The YEX-S1-TSS integrated online suspended solids sensor provided by YexSensor offers IIoT integrators a highly anti-interference, easy-to-maintain real-time sensing solution based on scattered light measurement technology, suitable for various complex site conditions.

Core Technology and Measurement Mechanism

Scattered Light Measurement Principle

The YEX-S1-TSS sensor is designed based on the scattered light method. When a beam of light is emitted into the water sample, the suspended particles in the sample cause light scattering. The photoelectric detector built into the sensor measures the intensity of the backscattered light and compares it with internal calibration values to calculate the suspended solids concentration in the water sample, outputting the final value after linearization processing.

• Scattered light principle, built-in temperature sensor

• Supports RS-485, Modbus/RTU protocol

• Fiber optic structure with strong resistance to external light interference

• Infrared LED light source with high stability

• IP68 protection, suitable for depths up to 20 meters

• Convenient, fast, stable, and easy to maintain

Technical Performance and Specifications

1. Technical Parameters

Note: The sensor connector is an M16-5 core waterproof male plug.

Installation and Electrical Connection

1. Installation

Installation distance requirements: Keep at least 5cm from the side wall and at least 10cm from the bottom.

2. Electrical Connection

The cable is a 4-core twisted-pair shielded wire with the following pin definition:

• Red wire: Power line (12～24VDC)

• Black wire: Ground line (GND)

• Blue wire: 485A

• White wire: 485B

Carefully check the wiring sequence before powering on to avoid unnecessary losses due to incorrect wiring. Considering the cable may be submerged in water (including seawater) or exposed to air for long periods, all connection points must be waterproofed, and the user-side cable should have a certain level of corrosion resistance.

Maintenance and Care

1. Maintenance Procedures

The cleanliness of the measurement window is crucial for maintaining accurate readings.

2. Maintenance Methods

• Sensor Outer Surface: Clean with tap water. If debris remains, wipe with a moist soft cloth. For stubborn dirt, use tap water with household detergent.

• Cable Inspection: The cable should not be taut during normal operation to prevent internal wire breakage.

• Window Inspection: Periodically check the measurement window for contamination.

3. Precautions

The sensor contains sensitive optical and electronic components. Ensure it is not subjected to severe mechanical impact. There are no user-serviceable parts inside the sensor.

4. Sensor Calibration

a) Zero Calibration: Use a beaker to measure a suitable amount of zero-suspension solution or a known concentration solution (0～200.0mg/L). Place the sensor vertically in the solution with the front end at least 10cm from the bottom. Calibrate zero after 1 minute of stabilization.

b) Slope Calibration: Place the sensor in a known concentration suspension solution (200.0～2000.0mg/L). After 1 minute of stabilization, calibrate the slope. Note: No air bubbles should be present in front of the sensor.

FAQ: Common Integration Questions

Q1: How can the YEX-S1-TSS sensor be integrated with third-party PLCs?
Answer: The sensor uses standard Modbus/RTU protocol. Integrators only need to configure serial port parameters (baud rate, parity, etc.) in the PLC program and poll the corresponding register addresses.

Q2: Will monitoring values fluctuate in biochemical tanks with many air bubbles?
Answer: Bubbles produce strong scattering signals, leading to high readings. It is recommended to avoid bubble-prone areas or install baffles to buffer flow and reduce instantaneous fluctuations.

Q3: Is the sensor suitable for long-term immersion in industrial wastewater?
Answer: Yes, the housing is made of POM/ABS, with an IP68 protection rating, offering strong corrosion resistance suitable for most industrial wastewater and surface water environments.

Q4: Why is there a distance requirement from the bottom?
Answer: This prevents measurement errors caused by multiple reflection effects when the sensor is close to the bottom and prevents sediment from interfering with the light path.

Q5: Are there limits to communication distance?
Answer: The RS-485 standard supports communication up to 1200 meters. For high-interference environments, use an isolated RS-485 repeater to stabilize the signal.

Q6: Does calibration require sending the sensor back to the factory?
Answer: No. YexSensor supports on-site two-point calibration. Users only need a standard solution of a certain concentration to complete online calibration.

Q7: Will the sensor be damaged if connected incorrectly?
Answer: The internal circuitry is designed with reverse polarity protection, but we strictly recommend following the defined wiring order; connecting 24VDC directly to 485A/B pins is prohibited.

Q8: How to deal with biofilm attachment on the optical window?
Answer: While the equipment has good resistance, for high-bioactivity water, we recommend regular manual wiping or adding an auxiliary cleaning module.

Summary

The YEX-S1-TSS online suspended solids sensor, with its precise scattered light measurement principle, stable Modbus bus communication, and high industrial protection rating, serves as an ideal sensing component for modern water treatment system integration. YexSensor is dedicated to providing system integrators with full-lifecycle technical support, from protocol docking and on-site debugging to maintenance, assisting every water project in achieving data transparency and intelligent management.

If you are planning water treatment projects or require detailed integration plans and Modbus register maps for the YEX-S1-TSS, please contact the YexSensor technical service team. We provide professional and reliable industrial water quality monitoring solutions.