1、 Core challenge: Why are ordinary electrodes unable to handle it?

There are three major destructive factors in high acidity and alkalinity working conditions:

Glass film dissolution: Strong alkaline solution (pH>12) can corrode sensitive glass films, resulting in delayed response and decreased slope

Acid error: High H ⁺ concentration in strong acid solution (pH<2) causes "acid error", and the reading deviates from the true value

Reference system poisoning: Ag/AgCl reference electrode forms insoluble substances when encountering sulfides, bromides, etc., blocking the liquid network

2、 Key selection elements: Four major technical indicators

1. Material of electrode membrane

Strong alkaline working condition: choose high lithium glass film (with 3-5 times increased alkali corrosion resistance)

Strong acid/HF containing conditions: Fluorine ion resistant glass film must be used (ordinary glass will be perforated in 1% HF for 24 hours)

Severe working condition: Antimony electrode (strong acid resistance, but slightly lower accuracy, ± 0.1pH)

2. Reference system

Open liquid network part: anti blocking design, suitable for suspended solids and viscous media

Double salt bridge structure: The outer salt bridge uses high concentration KCl+anti pollution electrolyte to delay reference poisoning

Solid polymer reference: Non porous design to prevent electrolyte contamination and blockage

3. Material of electrode body

Conventional corrosion: Polyether ether ketone (PEEK), resistant to organic solvents and weak acids and bases

Strong corrosion: Titanium alloy (Ti6Al4V) or Hastelloy, resistant to 98% sulfuric acid, 40%

Sanitary grade: 316L stainless steel, suitable for CIP/SIP cleaning in the food and pharmaceutical industries

4. Temperature and pressure

High temperature type: resistance ≤ 130 ℃ (ceramic liquid junction+high temperature gel)

High pressure type: withstand ≤ 10 bar (thickened glass film and strengthened sealing)

3、 Selection decision matrix

Electroplating industry: choose fluoride ion resistance+open liquid network electrode to deal with chromic acid

Chlor alkali industry: using high lithium glass and titanium alloy shell, resistant to concentrated alkali and chlorine gas environment

Chemical reaction kettle: adopting high-pressure type+double salt bridge design to adapt to pressure fluctuations and complex media

Wastewater treatment: equipped with anti pollution and PEEK material electrodes to cope with sludge erosion and chemical addition

5、 Maintenance and lifespan optimization

Proper selection can extend the electrode life to 18-24 months (6-12 months under normal operating conditions):

Calibration frequency: High acidity and alkalinity environments require weekly calibration, using pH 1.68/4.01/6.86/9.18/12.45 multi-point calibration

Cleaning plan: Soak strong alkali pollution in 5% dilute hydrochloric acid, and treat organic pollution with protease solution

Storage requirements: Long term disuse and soaking in 3mol/L KCl to avoid dehydration of the glass film

The selection of high acid-base pH electrodes is a technical decision rather than a simple procurement. Accurately matching the working conditions and electrode characteristics can avoid the dilemma of "calibration every three days and replacement every three months". Investing in professional grade electrodes not only yields precise data, but also long-term stable operational benefits and significantly reduced overall costs.