Online Monitoring Digital Soil PH Probe RS485 Modbus PH Sensor IP68 Waterproof

Digital Soil pH Probe RS485 pH Sensor

>>Technical Parameter

Power Supply: 9~36VDC
Output: RS485 MODBUS RTU

Measuring Material: Glass/Silver + Silver Chloride
Housing Material: PP
Waterproof Rating: IP68

Measuring Range: 0-14pH
Accuracy: ±0.05pH
Pressure Range: ≤0.3MPa

Temperature Compensation: NTC10K
Temperature Range: 0-80℃

Calibration: Sample Calibration, Standard Solution Calibration

Connection: 4-core Cable
Cable Length: Standard 10m cable, extendable up to 100m
Installation Thread: PG13.5

Application: Soil Online Monitoring

>>Overview

The core theory of pH electrode measurement is the Nernst equation. The sensor used in potentiometric analysis is called a galvanic cell. A galvanic cell is a system that converts chemical reaction energy into electrical energy. The voltage of this cell is referred to as the electromotive force (EMF). This EMF consists of two half-cells. One half-cell is the measuring sensor, whose potential is related to the activity of specific ions; the other is the reference half-cell, often called the reference sensor, which is typically connected to the measurement solution and the instrument.

>>Electrode Maintenance and Care

○ Before use, unscrew the protective cap and immerse the electrode bulb and liquid junction in the sample.

○ If salt crystals form near the electrode tip or inside the cap due to electrolyte evaporation, rinse with water. This indicates normal dialysis membrane function.

○ Check for air bubbles in the glass bulb by shaking the electrode vertically.

○ Keep the glass membrane hydrated for fast response. After measurement or calibration: Rinse the electrode thoroughly. Add storage solution (3 mol/L KCl) to the protective cap.

○ Ensure terminal connections remain dry. Clean with anhydrous alcohol if contaminated.

○ Avoid prolonged immersion in distilled water, protein solutions, or contact with silicone grease.

○ For aged electrodes with cloudy membranes or deposits, soak in 10% HCl, then rinse.

○ Regularly clean and calibrate the electrode. If calibration fails after maintenance, replace the electrode.

>>Lifespan

Under normal conditions with proper maintenance, electrodes last over 12 months. Even unused electrodes have a shelf life of 12–24 months (if stored correctly). Exposure to strong acids, bases, high temperatures, or corrosive liquids shortens lifespan. Electrodes are consumables and generally not covered by warranty.

>>Electrode Calibration

○ Use fresh pH/ORP standard buffer solutions of appropriate concentrations.

○ Remove the protective cap and rinse the electrode with distilled water.

○ Set the instrument to calibration mode (refer to the instrument manual for details).

○ After calibration, measure actual samples.