Ammonia Nitrogen Sensor

I. Product Overview

The HD-DJ5 is an integrated online sensor that measures ammonia nitrogen and pH simultaneously. It meets the ammonia nitrogen measurement requirements of most industrial and environmental applications.

A built-in pH electrode measures the acidity and alkalinity of the water and compensates the ammonia nitrogen reading in real time, so that the result remains reliable when the pH of the sample changes.

II. Key Features

1. Built-in pH electrode performs the acidity/alkalinity measurement and compensates ammonia nitrogen in real time according to the pH value.

2. RS485 (MODBUS) signal output.

3. The electrode is a composite electrode consisting of a working electrode made of polyvinyl chloride and ion-active material and a reference electrode.

4. Internal signal isolation technology for strong interference immunity.

5. Fast, accurate measurement with simple operation.

6. Automatic temperature compensation and pH compensation.

7. IP68 waterproof rating with 3/4 NPT thread for immersion mounting.

III. Technical Parameters

IV. Installation and Wiring

Do not install the sensor upside down or horizontally; install it at an angle of at least 15° to the horizontal. Keep at least 5 cm from the side wall and 10 cm from the bottom.

The cable is a 4-core shielded cable: red - power supply (12–24 VDC), blue - ground (GND), green - RS485-B, yellow - RS485-A. Check the wiring order carefully before powering on, to avoid unnecessary losses caused by incorrect connection. Cable colours may differ slightly between production batches; the colour print on the cable always prevails.

V. Maintenance and Care

Before testing, remove the protective caps from the ammonium ion electrode and the pH electrode and soak both electrodes in clean water for 2 hours. After activation, rinse them with deionised water and start the measurement. For storage longer than two weeks, keep the electrodes dry with the sensing elements covered by their protective caps.

To obtain high-accuracy results, repeat the following procedure: take the electrode out of the standard solution, rinse it, blot it dry and immerse it again for at least 2 minutes until a stable reading is obtained, so that the electrode is properly wetted and pre-conditioned.

Check that the terminal block is dry; if it is soiled, wipe it with anhydrous alcohol and blow dry. Avoid prolonged immersion in distilled water or protein solutions and keep the electrode away from silicone grease. A PVC membrane in long service may become semi-transparent or covered with deposits, in which case rinse it with distilled (or deionised) water. Recalibrate the electrode when measurement error appears.