Getting Started

First-Time Use Precautions

• The sensor is rigorously calibrated before leaving the factory and is ready for use upon arrival, requiring no further calibration initially.
• Note: The bottle cap of the probe contains protective liquid (3.3mol/L KCL). Even if the bottle cap is screwed tightly, some protective liquid may still leak around the bottle cap, forming white crystals. But as long as there is still protective liquid in the bottle cap, it will not affect the life and accuracy of the probe. So please use it with confidence. It is recommended that the white crystals be poured back into the protective liquid in the bottle cap.
• The protective bottle at the electrode tip contains an appropriate amount of soaking solution. Before measurement, loosen the cap, remove the electrode, and rinse with pure water.
• The glass bulb at the electrode tip must not come into contact with hard objects. Any damage or scratches will cause the electrode to malfunction.
• Before measurement, remove air bubbles from the electrode bulb; otherwise, the measurement will be affected. During measurement, stir the electrode in the solution to be measured and then let it stand still to accelerate the response.
• Clean the electrode with deionized water before and after measurement to ensure accuracy.

Installation Methods

1. Submersible Installation: The sensor lead wires emerge from the waterproof conduit, and the top 3/4 thread is connected to the waterproof conduit's 3/4 thread using Teflon tape. Ensure the top of the sensor and the wires are not wetted.

2. Pipe Installation: Connect the sensor to the conduit via its 3/4 thread.

Electrode Calibration Instructions

1. Prepare two standard solutions with different ORP values. At room temperature (around 25°C), place the ORP electrode in the standard solution with the lower ORP value (e.g., if using 86mV and 256mV solutions, select the 86mV solution). Input the command to perform the first calibration (see the communication protocol example for detailed commands).

2. After completing the first calibration, clean the ORP electrode and dry it with a paper towel or soft cloth (be careful not to damage the glass bulb of the electrode, otherwise the electrode will fail). Place the sensor in a standard solution with a higher ORP value (e.g., if using 86mV and 256mV solutions, select the 256mV solution). After the ORP value stabilizes, input the command to perform the second calibration (see the communication protocol example for detailed commands).

Long-Term Maintenance

◆ The equipment itself generally requires no routine maintenance. In case of obvious malfunction, please do not attempt to repair it yourself; contact us immediately!
◆ Preparation of the electrode soaking solution: Dissolve one packet of ORP 4.00 buffer in 250 ml of pure water, then add 56 g of analytical grade potassium chloride. Heat appropriately on an electric furnace, stirring until completely dissolved. Alternatively, a 3.3M potassium chloride solution can be used for soaking, prepared as follows: Dissolve 25 g of analytical grade potassium chloride in 100 ml of pure water.
◆ After long-term use, ORP electrodes may become passivated, resulting in a reduced sensitive gradient, slow response, and inaccurate readings. For non-metallic electrodes: Soak the lower bulb in 0.1M dilute hydrochloric acid for 24 hours (0.1M hydrochloric acid preparation: dilute 9 ml of hydrochloric acid with distilled water to 1000 ml), then soak in 3.3M potassium chloride solution for 24 hours. If the passivation of the ORP electrode is severe and soaking in 0.1M hydrochloric acid has no effect, immerse the bulb end of the ORP electrode in 4% HF (hydrofluoric acid) for 3-5 seconds, rinse with pure water, and then soak in 3.3M potassium chloride solution for 24 hours to restore its performance. For antimony electrodes: The metal tip can be polished with fine sandpaper until a metallic luster appears, restoring its performance.
◆ Contamination of the glass bulb or blockage at the liquid junction can also cause electrode passivation. In this case, cleaning with an appropriate solution should be used according to the nature of the contaminant, as detailed in the table below (for reference).

◆ The electrode's service life is 1 year. Replace the electrode promptly after aging.
◆ The equipment should be calibrated before each use. For long-term use, calibration every 3 months is recommended. The calibration frequency should be adjusted appropriately according to different application conditions (degree of dirt in the application environment, chemical deposits, etc.).