Product Overview

The mercuric oxide reference electrode uses the Hg/HgO reference system and provides good potential reproducibility, especially for potential measurements in alkaline solutions. Available configurations include all-PTFE, miniature, single-salt-bridge, extended, double-salt-bridge, reduced-diameter double-salt-bridge, L-shaped salt-bridge, and custom versions.

Applications

• Cyclic voltammetry, potentiostatic, and potential-scan testing in alkaline electrolytes.
• Alkaline batteries, metal corrosion, and electrocatalytic materials research.
• pH meters, ion meters, potentiometric titrators, and electrochemical workstations.
• Routine electrochemical cells, deep-liquid-level setups, and double-salt-bridge isolation tests.

For strongly acidic, strongly alkaline, or complex ionic environments, adding a salt bridge is recommended to reduce contamination and extend service life.

Technical Parameters

• Internal resistance: ≤10 kΩ.
• Standard electrode potential at 25°C: 98 mV.
• Liquid junction flow rate: approximately 1 drop per 10 minutes.
• Salt bridge solution: 1.0 mol/L KOH; reference potential: 114 mV.

Use

1. Remove the rubber cap from the liquid junction before use.
2. After filling, check for air bubbles. If present, hold the electrode upright and tap it gently until the bubbles rise and disappear.
3. Secure the electrode in a clamp or electrode holder, ensuring that the liquid junction is fully immersed in the test solution.
4. During measurement, keep the salt bridge solution level inside the electrode above the test-solution level to prevent backflow.
5. After testing, rinse the exterior with deionized water and keep the liquid junction moist.

Maintenance and Safety

• Do not use in media that react with the KOH salt bridge solution or form precipitates.
• Clean the electrode body regularly and replace the salt bridge solution in time to keep the liquid junction clear.
• For short-term storage, immerse the liquid junction in 1.0 mol/L KOH solution.
• For long-term storage, seal the electrode and keep it away from light.
• Do not use ultrasonic cleaning on the reference electrode.
• Mercuric oxide is toxic and the salt bridge solution is corrosive. Follow laboratory safety procedures during operation.

Frequently Asked Questions