NBL-DDM-206 Online Water Quality Conductivity Sensor

Drinking water / surface water / various water supply / industrial water treatment. Signal output: RS-485 (Modbus/RTU protocol). Convenient connection to third-party equipment such as PLC, DCS, industrial control computer, general controller, paperless recording instrument or touch screen. Immersion installation with 3/4 NPT pipe thread for easy submersible installation or installation in pipes and tanks. IP68 protection grade.

NBL-DDM-206 Water Quality Conductivity Sensor Technical Specifications

1. Application Environment Description

- Drinking water/Surface water/Various water supply/Industrial water treatment.

- Signal output: RS-485 (Modbus RTU protocol).

- Convenient connection to PLC, DCS, industrial control computers, general controllers, paperless recorders, or touchscreens, etc.

- Immersion installation with 3/4 NPT pipe thread, easy for submersion installation or installation in pipes and tanks.

- IP68 protection level.

- Simultaneously outputs conductivity and TDS for 0–20 μS/cm, 0–200 μS/cm.

2. Electrical Connection

The cable is a 4-core twisted shielded wire. The wiring sequence is defined as:

- Red wire — Power wire (12–24VDC)

- Black wire — Ground wire (GND)

- Blue wire — 485A

- White wire — 485B

Before powering up, carefully check the wiring sequence to avoid unnecessary losses due to incorrect wiring.

Wiring Note: Considering the cable will be submerged in water (including seawater) or exposed to the air for long periods, all wiring should be waterproof, and the user cable should have certain corrosion resistance.

3. Water Quality Conductivity Sensor Maintenance and Care

3.1 Use and Maintenance

Regular electrodes need periodic cleaning and calibration, with the maintenance cycle determined by the customer based on their working conditions. The cleaning method for regular electrodes: Use a soft brush to remove attachments (be careful not to scratch the electrode surface), then clean with distilled water, and perform calibration afterward.

Cleaning method for inductive electrodes:

- Inductive electrodes are generally maintenance-free. Pollution or light scaling on the outer shell does not affect normal operation.

- If cleaning is necessary, use a soft brush or sandpaper to remove attachments, then clean with distilled water and perform calibration afterward.

- Since inductive electrodes often operate in environments prone to scaling or dirt, greater force may be applied during cleaning. Light scratches on the electrode surface will not affect normal operation, but care should be taken not to penetrate the electrode shell.

3.2 Calibration

a) Zero Calibration:

Rinse the sensor with distilled water and absorb the liquid with filter paper. Place the sensor vertically in the air, let it stand for about 3 minutes until the value stabilizes, and then perform zero-point calibration. Calibration instructions can be found in the appendix.

b) Slope Calibration:

Place the sensor vertically in a standard solution (20% of full scale—full scale), ensuring that the sensor is at least 5cm from the bottom of the container and at least 2cm from the side walls, then perform slope calibration. Calibration instructions can be found in the appendix.

4. Quality and Service

Quality Assurance

- The quality control department follows standardized inspection procedures, equipped with advanced and complete testing equipment and methods. Products undergo 72-hour aging and stability tests, ensuring that no substandard products are shipped.