NBL-NOO-406-S Online Nitrite Sensor - Industrial Water Quality Monitoring for Aquaculture and Wastewater Treatment

NiuBoL NBL-NOO-406 Online Nitrite Sensor

In scenarios such as wastewater treatment, industrial process control, and aquaculture, fluctuations in nitrite concentration often lead to water quality imbalance, equipment corrosion, or biological toxicity risks. The NiuBoL NBL-NOO-406 integrated online nitrite sensor takes patented ion selective electrode as the core, combined with automatic temperature compensation and stable reference system, to achieve fast and accurate continuous monitoring of nitrite ions. It helps system integrators and engineering contractors build reliable water quality control solutions, reduce maintenance costs, and improve system stability.

Product Overview

NiuBoL NBL-NOO-406 (Online NO₂⁻ Sensor) is an online nitrite nitrogen sensor specially designed for industrial field applications. Based on the PVC membrane ion selective electrode principle, the range covers 0~2.000 mg/L, suitable for medium and low concentration nitrite monitoring needs. The sensor has built-in Pt1000 temperature compensation to ensure measurement accuracy of ±5% (concentration) and ±0.3℃ (temperature) in the 0~40℃ working environment. It uses RS-485 bus Modbus RTU protocol output, which is convenient for seamless docking with third-party controllers, PLC, DCS, or paperless recorders, truly realizing "plug-and-play" engineering integration.

The product emphasizes long-term stability: the internal reference liquid slowly seeps out through the microporous salt bridge under pressure ≥100KPa, forming a reliable reference system, significantly extending electrode service life and reducing drift and maintenance frequency. The housing is made of 316L stainless steel with IP68 protection rating, supporting submersible installation and suitable for complex water environments.

Core Advantages of NBL-NOO-406-S Online Nitrite Sensor

NiuBoL NBL-NOO-406 has significant engineering advantages in hardware design, signal stability, and integration friendliness, making it suitable for B2B projects with strict reliability requirements.

Patented Stable Reference System
The sensor adopts a patented nitrite ion electrode. The internal reference liquid seeps out extremely slowly under at least 1Bar pressure, effectively suppressing liquid junction potential fluctuations. Compared with ordinary industrial electrodes, this design greatly improves long-term stability, reduces drift problems caused by reference liquid depletion or contamination, and is suitable for continuous operation online monitoring systems.

High Precision and Anti-Interference Capability
The measurement principle is ion selective method, paired with automatic temperature compensation (Pt1000), maintaining high consistency in the 0~40℃ range. RS-485 differential signal transmission combined with Modbus RTU protocol provides excellent anti-electromagnetic interference capability. Even in complex wiring environments at industrial sites, data transmission reliability is still ensured. The two-point calibration method (zero point + slope) is simple to operate and can quickly restore measurement accuracy.

Rugged and Protective Design
The housing material is 316L stainless steel with outstanding corrosion resistance; IP68 protection rating supports long-term immersion installation. The installation interface adopts 3/4 NPT thread. Installation with a tilt of more than 15° is required to avoid measurement errors caused by inversion or horizontal placement. The sensor power consumption is only 0.2W@12V, adapting to wide voltage power supply of 12~24VDC and reducing system energy consumption.

Easy Integration and Low Maintenance Features
Standard 5-meter 5-core twisted shielded cable (M16-5-core waterproof connector) with clear wiring sequence: red (power), black (GND), blue (485A), white (485B), yellow (optional current output, can be left floating). It can be connected to existing industrial control networks without complex configuration. For maintenance, only regular cleaning of the electrode with distilled water is required, avoiding contact with silicone grease. Electrode life is significantly better than traditional products.

These advantages together ensure that the NBL-NOO-406 online nitrite sensor (Online NO₂⁻ Sensor) provides stable and reliable nitrite data support in harsh industrial environments, helping engineering projects achieve precise process control and compliance monitoring.

NBL-NOO-406-S Online Nitrite Sensor Technical Specifications

Note: Current output is an optional function; the yellow wire can be left floating when not in use.

Application Scenarios of NBL-NOO-406-S Online Nitrite Sensor

NiuBoL NBL-NOO-406 is widely used in industrial and environmental protection fields that require real-time nitrite monitoring. The following are typical application scenarios:

1. Urban Wastewater Treatment Plants: Monitor nitrite concentration in aeration tanks and denitrification sections, optimize denitrification process parameters, prevent nitrite accumulation leading to effluent exceedance, and ensure compliant discharge.

2. Industrial Wastewater Treatment Systems: Online monitoring of nitrite ions in production process water in chemical, fertilizer, metallurgy and other industries to help control process reaction progress and reduce secondary pollution risks.

3. Aquaculture and Aquarium Systems: Real-time monitoring of nitrite levels in aquaculture water bodies. Aquatic organisms such as fish and shrimp are highly sensitive to nitrite; exceedance can easily cause poisoning. The sensor supports continuous monitoring and assists in automatic water quality regulation.

4. Drinking Water and Surface Water Source Monitoring: Used by waterworks or environmental monitoring stations for nitrite nitrogen detection in source water and finished water to ensure drinking water safety and meet environmental regulatory requirements.

In addition, the sensor can also be extended to food processing wastewater, boiler makeup water treatment and other fields, providing system integrators with flexible multi-scenario solutions.

Installation and Wiring Instructions

Installation Precautions: The sensor must not be installed inverted or horizontally. It should be installed with a tilt of at least 15° or more to ensure normal operation of the reference system. It is recommended to use a 3/4 NPT threaded interface to fix it on pipelines, tanks, or brackets.

Electrical Connection: Uses 5-core twisted shielded cable with the following wiring sequence:

• Red wire: Power positive (12～24VDC)

• Black wire: Ground (GND)

• Blue wire: RS485 A

• White wire: RS485 B

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

Before powering on, be sure to check the wiring sequence to avoid reverse connection damaging the equipment. In long-term immersion or exposed environments, all wiring must be reliably waterproofed, and corrosion-resistant cables should be used. It is recommended to check the wiring terminals in a dry environment. If there is dirt, wipe with anhydrous alcohol, blow dry, and then use.

FAQ

Q1: What concentration range is the NBL-NOO-406 sensor suitable for nitrite monitoring?

A1: The range is 0~2.000 mg/L with a resolution of 0.001 mg/L, suitable for most medium and low concentration industrial water quality and environmental monitoring scenarios. For higher ranges, please consult NiuBoL for customized solutions.

Q2: How to calibrate the sensor?

A2: It is factory calibrated and only requires two-point calibration (zero point standard solution + slope standard solution) when the error exceeds the limit. Immerse the sensor in the standard solution for 5 minutes. After the value stabilizes, complete calibration through Modbus commands. The operation is simple.

Q3: How to integrate the RS485 Modbus RTU protocol into the existing PLC system?

A3: The sensor supports the standard Modbus RTU protocol and can be directly connected to PLC, DCS, or industrial computer via 485 bus. NiuBoL provides communication protocol documents with short integration cycle and strong compatibility.

Q4: Can the sensor be used long-term in high-salinity or corrosive water bodies?

A4: The housing is made of 316L stainless steel with IP68 protection and a stable reference system, suitable for various water bodies including seawater. However, long-term immersion in distilled water or protein solutions should be avoided, and the electrode status should be checked regularly.

Q5: What is the electrode maintenance frequency?

A5: Clean the front end of the electrode daily with distilled or deionized water and dry it before use. It is recommended to soak in tap water for 24 hours for activation before first use. Rinse with clean water when sediment appears. Perform calibration when long-term error increases; replace the electrode if it cannot be restored (consumable, 6-month warranty).

Q6: Must the sensor be installed with a tilt of more than 15°? Why?

A6: Yes. Inverted or horizontal installation will affect the stability of reference liquid seepage, leading to measurement drift. Tilted installation ensures normal operation of the microporous salt bridge and maintains reference system reliability.

Q7: Will unstable power supply voltage affect measurement?

A7: The sensor supports wide voltage input of 12～24VDC with built-in voltage regulation design and low power consumption (0.2W@12V), providing good adaptability to power fluctuations. However, a regulated power supply is recommended for optimal performance.

Q8: What is the warranty policy? Are accessories easy to obtain?

A8: The whole machine has a one-year warranty from the date of sale, and the electrode, as a consumable, has a six-month warranty (except for improper use). The product comes standard with sensor, 5-meter cable, manual, and certificate of conformity. Accessories can be quickly obtained through official NiuBoL channels.

Summary

The NiuBoL NBL-NOO-406 integrated online nitrite sensor provides an efficient solution for water quality monitoring projects with its stable and reliable ion selective electrode technology, convenient Modbus integration, and rugged industrial-grade design. It not only helps engineering contractors and system integrators reduce operation and maintenance costs but also provides precise data support for process optimization and environmental compliance.

If you are planning wastewater treatment, industrial water treatment, or aquaculture monitoring systems, please contact the NiuBoL technical team. We can provide selection advice, communication protocol support, and on-site integration guidance according to specific working conditions to help your project land efficiently.

NiuBoL — Focused on industrial IoT sensing, building a reliable water quality monitoring network.

NBL-NOO-406-S Online Nitrite Sensor Data Sheet

NBL-NOO-406-S Online Nitrite Sensor.pdf