E+H pH Electrode Production Process Overview
E+H (Endress+Hauser), as a well-known brand in the field of industrial measurement, is renowned for its high-precision and long-life pH electrodes. The production process integrates precision glass craftsmanship and electrochemical technology to ensure stable operation of the electrodes under harsh conditions.
The following video and step-by-step analysis will guide you through the core manufacturing steps of E+H pH electrodes.
Video from Endress+Hauser YouTube official website
Detailed Explanation of Key Production Steps
1. Glass Membrane Preparation and Forming
The core of a pH electrode is the sensitive glass membrane, whose composition and thickness directly affect measurement accuracy and response time. E+H uses specially formulated glass, which is melted at high temperature and precision blown to form a spherical thin film.
- Glass raw materials must be of high purity to avoid impurities affecting the potential
- Membrane thickness is controlled at 0.1~0.3 mm, balancing mechanical strength and response speed
- After forming, annealing is required to eliminate internal stress and prevent cracking
2. Reference System Assembly
The reference electrode provides a stable reference potential, and its structure includes an Ag/AgCl internal reference, electrolyte, and liquid junction. E+H uses gel or polymer electrolytes to reduce maintenance requirements.
- The liquid junction design affects anti-clogging ability; common types include ceramic frit, PTFE ring, etc.
- The reference system must be assembled coaxially with the glass membrane to ensure symmetry of the electrochemical circuit
- Assembly is performed in a clean environment to prevent contamination
3. Electrolyte Filling and Sealing
Electrolyte filling is key to ensuring long-term stability of the electrode. E+H uses a high-pressure filling process to ensure the internal filling solution is bubble-free and at constant pressure.
- Invert the electrode and vacuum to remove air
- Inject pre-prepared KCl electrolyte
- Pressurize to allow the electrolyte to penetrate the liquid junction
- Seal the electrode tail and install the cable connector
4. Calibration and Quality Inspection
Each electrode must undergo multi-point calibration and performance testing before leaving the factory to ensure slope and zero point meet standards.
| Test Item | Standard Requirement | Test Method |
|---|---|---|
| Slope | 95%~105% | pH 4.00/7.00/10.00 buffer solutions |
| Zero point potential | 0±30 mV (pH 7.00) | High-impedance millivoltmeter |
| Response time | ≤30 seconds (reach 95% stable value) | Switch from pH 7.00 to 4.00 |
| Internal resistance | 50~200 MΩ | Dedicated impedance tester |
Key Quality Control Points in Production
E+H has set strict quality control points at every stage of production to ensure consistency and reliability of the electrodes.
- Incoming material inspection: Glass tubes, Ag/AgCl wires, electrolytes, etc. must pass composition and performance tests
- Process control: Real-time monitoring of glass membrane thickness, reference electrode potential, and filling pressure
- Finished product aging: Electrodes are soaked in standard buffer solution for more than 24 hours, then calibrated after stabilization
- Traceability: Each electrode has a unique serial number, recording all production data
Common Questions and Selection Recommendations
Understanding the production process helps with correct selection and use. Engineering technicians and procurement personnel can focus on the following points:
- Choose the glass membrane type based on medium characteristics (e.g., hydrofluoric acid resistant, high temperature resistant)
- The liquid junction material of the reference system must match process conditions to prevent clogging
- Consider installation method (immersion, flow-through) and connection interface
- Regular calibration and maintenance to extend electrode life
With precision manufacturing processes and strict quality control, E+H pH electrodes provide reliable pH measurement solutions for industrial processes.