Root Cause: Irreversible scale buildup on the probe electrode surface + electrochemical wear of the electrode material; simple calibration alone cannot eliminate underlying damage, resulting in recurring drift

I. Composite salt deposits on the electrode surface alter the conductive contact area

During operation with high-concentration saturated brine, inorganic salts continuously crystallize on the metal plates and in the gaps of the electrodes, forming a dense, hard salt film; colloidal silicic acid and organic slime combine with the salt crystals to form an insulating composite deposit.

The scale layer prevents effective contact between the electrode and the process solution, causing the effective conductive area to continuously decrease and resulting in persistently low measurement readings;

Calibration relying solely on software correction factors cannot remove the physical scale layer; after cleaning, the scale re-forms within a few hours of normal operation, causing the readings to drift immediately.

II. Electrochemical corrosion of the electrodes leads to permanent degradation of the effective conductive area

Prolonged immersion in high-chloride-ion concentration solutions causes pitting and intergranular corrosion on the stainless steel or titanium alloy surfaces of the electrodes:

Irregular corrosion pits form on the electrode surfaces, disrupting conductive uniformity and causing permanent changes in the electrode constant;

The factory-calibrated electrode constant becomes invalid; recalibration after each cleaning only provides temporary restoration, while corrosion continues to progress, resulting in increasingly larger measurement drifts.

III. Salt accumulation in crevices forms a closed-circuit cell, causing moisture ingress and electrical leakage in the probe’s internal wiring

Salt-containing solution seeps into the electrode terminal block and sealing crevices, forming microscopic conductive leakage paths:

Since the measurement relies on a weak conductivity signal, leakage current continuously interferes with the detection reference, causing readings to drift erratically up and down;

Internal wiring corrosion constitutes internal damage that cannot be repaired by external cleaning or instrument calibration, resulting in a persistent shift in the signal reference.

IV. Frequent fluctuations in the concentration level cause the electrodes to alternate between wet and dry states, accelerating scaling and aging

The concentration level range is narrow, causing the probe to repeatedly alternate between immersion and exposure to the gas phase:

Salt crystals at the liquid surface dehydrate and harden, forming a scale layer with stronger adhesion that is difficult to rinse off;

The alternating wet and dry cycles accelerate the rate of electrode corrosion, speeding up the decay of the electrode constant and significantly shortening the calibration validity period.

V. Temperature compensation module is disrupted by high-temperature salt fog, causing uncontrolled temperature drift

The probe contains a built-in temperature compensation element; after prolonged exposure to high temperatures and high-concentration salt fog, the compensation accuracy fails;

At the same concentration but different temperatures, the conductivity conversion logic exhibits a fixed deviation; simply calibrating the conductivity coefficient cannot offset the continuous drift caused by temperature.