KWS-200 Online NH4-N Ammonia Nitrogen Sensor
Application Environment
Kacise introduces an online ammonia nitrogen sensor that requires no reagents, is green and non-polluting, and can be monitored online in real time. Integrated ammonium, potassium (optional), pH and reference electrodes automatically compensate for potassium (optional), pH and temperature in water. It can be directly put into installation, which is more economical, environmentally friendly and convenient than traditional ammonia nitrogen analyzer. The sensor has a self-cleaning brush that prevents microbial adhesion, resulting in longer maintenance intervals and excellent reliability. It adopts RS485 output and supports Modbus for easy integration.
Feature
- Digital sensor, RS-485 output, support MODBUS
- No reagents, no pollution, more economical and environmentally friendly
- Automatically compensates for pH and temperature in water
- Self-cleaning brush to prevent microbial adhesion and longer maintenance intervals
Technical Specifications
Model | KWS-200 |
Measuring Range | 0-1000mg/L NH4-N |
Accuracy | 5% |
NH4-N Resolution | 0.1 mg/L |
Ph Range | 4-10 |
Ph Accurate | ±0.1 |
Ph Resolution | 0.01 |
Protection Grade | IP68 |
Deepest Depth | underwater 10 m |
Temperature Range | 0 ~ 50℃ |
Output | RS-485, MODBUS protocol |
Power Supply | DC 8~26V, current <50mA |
Size | Φ26*177.5 mm |
Cable Length | 5 m, customizable |
Material | POM |
Dimensional Drawing


Installation and Electrical Connection
1. Installation

Note: The sensor should not be installed upside down or horizontally when installed, at least at an angle of 15 degrees or more.
2. Electrical Connection
a) Red line - power cord (12 ~ 24V)
b) Black line - ground (GND)
c) Blue line - 485 A
d) White line - 485 B
e) Bare wire - shielded wire
After wiring is completed, it should be carefully checked to avoid incorrect connections before powering up.
Cable specification: Considering that the cable is immersed in water (including sea water) for a long time or exposed to the air, the cable has certain corrosion resistance. The outer diameter of the cable is Φ6 mm and all interfaces are waterproof.
Maintenance
1. Use and Maintenance
Rinse the electrode in distilled water (or deionized water), blot dry, and do not dry. Place the electrode on the electrode holder. Prior to use, the tip of the electrode was immersed in distilled water (or deionized water) for 10 minutes and then immersed in the diluted ammonium ion solution for 2 hours.
Keep the electrode dry before use. The sensing element of the electrode should be placed in the protective bottle. The electrode should be immersed in the activation solution for 24 hours before testing. If stored overnight or longer, clean the electrode tip with deionized water, wipe dry, and place in the original packaging.
Check if the terminal is dry. If it is stained, wipe it with absolute alcohol and dry it. Avoid long-term immersion in distilled water or protein solution and prevent contact with silicone grease. With longer electrodes, its PVC film may become translucent or with deposits, which can be rinsed with distilled water (or deionized water). The electrode is used for a long time. When a measurement error occurs, it must be calibrated with the meter.
When the calibration and measurement cannot be performed while maintaining and maintaining the electrode in the above manner, the electrode has failed. Please replace the electrode.
The main interference ions are shown in the table below:
Interference ion concentration that produces 10% error at different ammonium ion concentrations
Interferences (moles/liter) | 10-4 M Ammonium | 10-3 M Ammonium | 10-2 M Ammonium |
H+ | < 2 | < 1 | < 1 |
Li+ | 0.2 | 0.5 | 0.5 |
Na+ | 0.005 | 0.08 | 0.8 |
K+ | 7*10-5 | 6*10-4 | 6*10-3 |
Cs+ | 0.003 | 0.05 | 0.5 |
Mg3+ | > 0.5 | > 1 | > 1 |
Ca2+ | > 0.2 | > 1 | > 1 |
Sr2+ | > 0.2 | > 1 | > 1 |
Ba2+ | > 0.1 | > 0.5 | > 0.5 |
Zn2+ | 0.001 | 0.01 | 0.1 |
N2H5+ | > 0.1 | > 0.1 | >0.1 |
Bu4N+ | 1*10-5 | 1*10-4 | 1*10-3 |
2. Sensor Calibration
Note: The sensor has been calibrated before leaving the factory. If it is not beyond the measurement error, it should not be arbitrarily calibrated.
a) Zero calibration
Place the sensor in a vial containing the zero standard solution and wait for 5 minutes. After the value is stable, see if the displayed value is within the error range. If not, perform a zero calibration. Refer to the appendix for calibration instructions.
b) Slope calibration
Place the sensor in a vial containing the standard solution of the slope and wait for 5 minutes. After the value is stable, see if the displayed value is within the error range. If not, the slope calibration is required. Refer to the appendix for calibration instructions.
Quality and Service
1. Quality Assurance
- The quality inspection department has standardized inspection procedures, advanced and perfect testing equipment and means, and strictly in accordance with the regulations, to do 72-hour aging test and stability test on the product, and not to allow one unqualified product to leave the factory.
- The receiving party directly returns the product batch with a failure rate of 2%, and all the costs incurred are borne by the supplier. The reference standard refers to the product description provided by the supplier.
- Guarantee the quantity of goods and the speed of shipment.
2. Accessories and Spare Parts
This product includes:
- 1 sensor
- 1 copy of the manual
- 1 certificate
- 1 ml/L and 10 mg/L calibration solution each 100 ml
- Pre-activation solution 100 ml
3. After –sales Service Commitment
The company provides local after-sales service within one year from the date of sale, but does not include damage caused by improper use. If repair or adjustment is required, please return it, but the shipping cost must be conceited. Damaged on the way, the company will repair the damage of the instrument for free.
Contact Us
Website www.kacise.com
Phone +86-17719566736
Email sales@kacise.com
Location Tangyan South Road, High-tech Zone, Xi'an City, Shaanxi Province, China
