YEX-NON-406 Online Nitrate Nitrogen Sensor RS-485 (Modbus RTU)/4-20 mA PVC Membrane Nitrate Ion Selective Electrode

Yexsensor YEX-NON-406 Online Nitrate Nitrogen Sensor

Yexsensor YEX-NON-406 online nitrate nitrogen sensor is a split-type online monitoring device developed for system integrators, IoT solution providers and water treatment engineering companies. The sensor is based on the PVC membrane nitrate ion selective electrode principle and is equipped with automatic temperature compensation function, which can realize high-precision continuous measurement of nitrate ion (nitrate nitrogen) content in water, meeting the stringent requirements of municipal sewage treatment denitrification process control, industrial wastewater discharge monitoring and environmental water nitrogen pollution supervision.

With increasingly strict total nitrogen emission standards, nitrate nitrogen, as a key intermediate product in the denitrification process, has important significance for process optimization and compliance discharge through real-time monitoring. Traditional laboratory analysis methods have problems such as sampling lag and high labor costs, while YEX-NON-406 provides reliable process data for PLC, DCS, SCADA or IoT platforms through stable ion selective electrode technology and standard digital output, supports automatic control strategy adjustment, effectively reduces energy consumption and improves system operation stability.

YEX-NON-406 Online Nitrate Nitrogen Sensor Working Principle

YEX-NON-406 adopts the ion selective method (ISE). The core component of the sensor is a patented PVC membrane nitrate ion selective electrode. The ionic active substance in the membrane has a highly selective response to NO₃⁻ ions. When the electrode contacts the water sample to be measured, nitrate ions undergo selective ion exchange on the membrane surface, generating a potential difference signal related to ion activity.

The internal reference system is uniquely designed: the reference liquid seeps out extremely slowly through the microporous salt bridge under a pressure of at least 100 kPa (1 Bar), forming a highly stable liquid junction potential. This patented reference structure significantly improves the long-term stability of the electrode, extends the service life, and reduces drift. The built-in Pt1000 temperature sensor realizes automatic temperature compensation, ensuring the accuracy and repeatability of measurement results within the operating range of 0～40℃.

YEX-NON-406 Online Nitrate Nitrogen Sensor Product Features

YEX-NON-406 embodies multiple core advantages in engineering applications:

• Patented PVC membrane nitrate ion selective electrode, stable reference system, electrode life is better than conventional industrial electrodes

• Supports RS-485 Modbus/RTU protocol and optional 4-20 mA current output, convenient for connecting to various third-party control equipment

• Automatic temperature compensation (Pt1000), effectively reducing the impact of temperature fluctuations on measurement accuracy

• Provides two shell material options (YEX-NON-406-A: POM+ABS; YEX-NON-406-S: POM+316L), adapting to different corrosive environments

• 3/4 NPT threaded interface, supports flexible submersible, pipeline or tank installation

• IP68 protection level, suitable for long-term immersion conditions

• Low power consumption design (0.2 W @ 12 V), fast response time (T90 < 60 s)

• Two-point calibration method, easy operation and low maintenance cost

These features make YEX-NON-406 a preferred solution that is easy to integrate and reliable in operation for nitrate nitrogen online monitoring projects.

YEX-NON-406 Online Nitrate Nitrogen Sensor Technical Parameters

Model Comparison

General Technical Specifications

YEX-NON-406 Online Nitrate Nitrogen Sensor Installation and Electrical Connection

Installation Requirements

YEX-NON-406 must adopt submersible installation method. It cannot be installed upside down or horizontally. It must be tilted at least 15 degrees to ensure normal slow seepage of reference liquid and normal operation of the electrode. The 3/4 NPT threaded interface is convenient for direct installation in reaction tanks, pipelines or storage tanks. The installation position should ensure that the sensor is in full contact with the water body to be measured, and it is convenient for later maintenance and sampling.

Electrical Connection

The sensor is equipped with a 5-core twisted shielded cable, and the wire sequence is defined as follows:

• Red wire: Power positive pole (12～24 V DC)

• Black wire: Ground wire (GND)

• Blue wire: RS-485 A

• White wire: RS-485 B

• Yellow wire: Current output (optional; if not used, it can be left floating)

Before wiring, please carefully check the sequence. All wiring terminals must be waterproofed. The cable should have anti-corrosion ability to adapt to long-term immersion in sewage or exposure to humid environments.

YEX-NON-406 Online Nitrate Nitrogen Sensor Maintenance and Care

The maintenance focus of YEX-NON-406 is the correct cleaning, storage and regular inspection of the electrode to maximize the electrode service life.

Maintenance Methods

• Preparation before use: For new electrodes or after long-term storage, soak the front end of the electrode in tap water for 24 hours (power-on soaking is better).

• Cleaning: Rinse the electrode head with distilled water or deionized water, and gently blot the surface moisture (do not wipe the PVC sensing membrane).

• Storage: Place short-term on the electrode holder; for long-term storage, clean with deionized water, wipe dry, and put back into the original packaging protection bottle.

• Wiring inspection: Regularly confirm that the wiring terminals are dry. If contaminated, wipe with absolute alcohol and blow dry.

Avoid long-term immersion in distilled water or protein solutions, and prevent contact with organic silicone grease. When the PVC membrane appears translucent or has obvious deposits, rinse with distilled water. If it still cannot be calibrated and measured normally after maintenance, the electrode has failed and needs to be replaced in time (the electrode is a consumable).

In actual engineering applications, it is recommended to evaluate potential interference based on the on-site water quality composition and take pretreatment measures when necessary.

Calibration Method

The sensor has been calibrated before leaving the factory. It is not recommended to calibrate arbitrarily unless the measurement error range is exceeded.

• Zero point calibration: Put the sensor into the zero point standard solution vial, wait for 5 minutes until the value is stable, then execute the command.

• Slope calibration: Put it into the slope standard solution vial, wait for 5 minutes until stable, then execute the command.

YEX-NON-406 Online Nitrate Nitrogen Sensor Application Scenarios

Yexsensor YEX-NON-406 is widely used in water treatment and environmental monitoring projects with nitrate nitrogen control as the core.

• Municipal Wastewater Treatment Plants
         Deployed in anoxic/anaerobic tanks, aerobic tank effluent and total nitrogen effluent outlets to grasp nitrate nitrogen concentration changes in real time, provide data support for denitrification carbon source dosing, aeration control and process parameter optimization, improve denitrification efficiency and reduce operating costs.

• Industrial Wastewater Treatment Systems
         Suitable for industries such as chemical, pharmaceutical, food processing, and fertilizer that produce high-nitrogen wastewater. The sensor is directly connected to the existing DCS or PLC system to achieve continuous process monitoring and reduce the frequency of manual laboratory analysis.

• Surface Water and River & Lake Environmental Monitoring
         As the core unit of fixed monitoring stations or mobile monitoring platforms, it provides continuous nitrate nitrogen data to support water eutrophication assessment, pollution source tracing and water quality early warning.

• Agricultural Irrigation and Aquaculture Wastewater Treatment
         Monitor nitrate nitrogen content in farmland return water or aquaculture tail water to help improve nitrogen fertilizer utilization and prevent agricultural non-point source pollution.

• Pipeline and Closed Tank Online Monitoring
         With the 3/4 NPT interface, it can be flexibly installed inside process pipelines or storage tanks to achieve real-time nitrate nitrogen detection in closed systems.

In these scenarios, YEX-NON-406 effectively simplifies the system architecture and meets the requirements of long-term unattended operation with its stable reference system, standard communication protocol and low maintenance characteristics.

Frequently Asked Questions (FAQ)

Q1. What measurement principle does YEX-NON-406 adopt?

The sensor is based on the ion selective method and measures using the specific potential response of the patented PVC membrane nitrate ion selective electrode to NO₃⁻.

Q2. What two shell materials are available for the sensor?

YEX-NON-406-A (POM+ABS) and YEX-NON-406-S (POM+316L), which are convenient for selecting the appropriate model according to on-site corrosiveness.

Q3. What output methods are supported for system integration?

Standard RS-485 Modbus/RTU protocol, optional 4-20 mA current output, compatible with PLC, DCS, recorders and other equipment.

Q4. What are the specific requirements for the installation angle?

The sensor cannot be installed upside down or horizontally. It must be tilted at least 15 degrees to ensure normal seepage of the reference liquid.

Q5. What are the key steps for daily electrode maintenance?

Soak in tap water for 24 hours before use, rinse with distilled water and blot dry during cleaning, and avoid wiping the sensing membrane.

Q6. Is the electrode a consumable? What is the warranty period?

The electrode is a consumable with a warranty of six months. The patented reference system design gives it a longer life, and the actual life depends on water quality conditions.

Q7. What is the adaptation range of the sensor for temperature and pressure?

Operating temperature 0～40℃, pressure ≤0.2 MPa, built-in Pt1000 automatic temperature compensation.

Q8. What about product warranty and after-sales service?

The product has undergone strict inspection and 72-hour aging test before leaving the factory. One-year whole machine warranty is provided from the date of sale, and the electrode has a six-month warranty. The manufacturer provides technical support, spare parts supply and factory repair services for system integrators.

Summary

Yexsensor YEX-NON-406 online nitrate nitrogen sensor takes patented PVC membrane ion selective electrode technology and stable reference system as the core, combined with automatic temperature compensation and industrial-grade communication interface, providing an accurate, reliable and economical solution for online nitrate nitrogen monitoring. Its flexible installation method, low maintenance requirements and multi-output compatibility fully meet the actual application scenarios of sewage treatment, industrial wastewater and environmental monitoring projects.

Through continuous and accurate nitrate nitrogen data, the sensor helps engineering projects optimize denitrification processes, ensure compliance with emissions, and effectively control long-term operation and maintenance costs. It has become an important choice for many system integrators in the field of nitrogen pollutant monitoring.

For detailed product quotations, technical specification sheets, selection guidance, customized cable lengths or project application cases, please contact the Yexsensor professional team. We will provide targeted configuration solutions and technical support according to your specific working conditions, control systems and water quality conditions to help your project be implemented efficiently and operate stably for a long time.