Soil pH Electrode Analog pH Sensor

>>Technical Parameter

‌pH Range:‌ 0-14 pH

‌pH Zero Point:‌ 7.00±0.25

‌Temperature Range:‌ 0-80℃

‌Pressure Resistance:‌ 0-0.3 MPa

‌Temperature Sensor:‌ None (standard), customizable options: NTC10K / PT100 / PT1000

‌Housing Material:‌ Glass

‌Membrane Resistance:‌ <800 MΩ

‌Reference System:‌ Ag/AgCl

‌Liquid Junction:‌ Porous Ceramic

‌Electrolyte Solution:‌ 3.3M KCl gel

‌Dual Salt Bridge System:‌ Yes

‌Connection Thread:‌ None or customizable PG13.5

>>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.

‌Cable Length:‌ 5m or customizable

‌Cable Connector:‌ Pin, BNC, or customizable