HH2500HF Water Online Process pH Electrode for Hydrofluoric Acid Applications Electrode | HF-Resistant Glass Membrane |Reinforced Cylindrical pH Glass Membrane

The HH2500HF is a combination pH electrode developed for aqueous processes where hydrofluoric acid can rapidly attack conventional pH-sensitive glass. Its specialized HF-resistant membrane is intended to reduce glass degradation and extend useful operating life in compatible fluoride-containing media.

The stated application limit is up to 5,000 ppm HF. This value must be considered together with the sample’s pH, temperature, exposure duration, flow, total fluoride content, and concentrations of other acids or chemicals. HF resistance does not mean complete immunity to chemical attack, particularly at elevated temperatures or under continuous exposure.

A dual-junction reference system provides an additional barrier between the process and internal reference element. The customized PCG polymer-gel electrolyte can be selected according to the process chemistry, while the standard special porous-ceramic junction provides ionic contact with the sample. Dual-point, triple-point, and ring-shaped PTFE junction options are available for different fouling and contamination conditions.

The electrode measures across pH 0–14 and is available with several integrated temperature-sensor options. Its glass body uses a PG13.5 process connection and can be supplied in insertion lengths from 120 to 425 mm for integration into compatible immersion, inline, and retractable assemblies.

Standard configurations operate at pressures up to 3 bar. Reinforced versions may be configured for pressures up to 6 bar, subject to the applicable temperature and the ratings of the complete installation.

Key benefits

• HF-resistant sensing membrane: Developed for aqueous media where hydrofluoric acid can damage conventional pH glass.
• Stated HF concentration up to 5,000 ppm: Subject to the verified temperature, pH, exposure, and process-composition limits.
• Dual-junction reference: Adds a second barrier between the process and internal reference element.
• Customized reference electrolyte: PCG polymer-gel formulation can be selected for the intended process chemistry.
• Configurable process junction: Single-, dual-, or triple-point ceramic and ring-shaped PTFE options are available.
• Flexible process integration: PG13.5 connection and insertion lengths from 120 to 425 mm.
• Multiple transmitter interfaces: Several connector and integrated temperature-sensor options are available.

Configuration options

• Insertion length: Selectable from 120 to 425 mm according to the process installation.
• Junction configuration: Single-, dual-, or triple-point porous ceramic, or ring-shaped PTFE junction.
• Reference electrolyte: Custom formulations are available for different process compositions.
• Reinforced pressure construction: Available for applications requiring pressures above the standard 3 bar rating.
• Connector configuration: S8, S8M, S7, VP8, K8S, K2, and other compatible formats.
• Extended cable: Cable lengths up to 60 metres, subject to transmitter and installation compatibility.
• Integrated temperature sensor: Selectable NTC, Pt100, and Pt1000 options.

Application and selection notes

Product selection should be based on more than the nominal HF concentration. Please provide the expected minimum and maximum pH, free-HF concentration, total fluoride, temperature, pressure, exposure pattern, other acids or oxidants, suspended solids, and cleaning chemicals.

The concentration of undissociated HF changes with pH and sample composition. Two samples with the same total fluoride concentration may therefore present different levels of attack on the sensing membrane.

Although the sensing membrane is formulated for HF exposure, the compatibility of the glass body, junction, reference system, seals, holder, and cable must also be confirmed.

Install the electrode where the sample is representative and mixed, while avoiding direct reagent injection, sediment accumulation, abrasive high-velocity flow, and mechanical impact.

Hydrofluoric acid is highly hazardous. Installation, removal, cleaning, calibration, and disposal must follow the applicable SDS, PPE requirements, exposure controls, emergency procedures, site rules, and electrode instructions.

Application

• Semiconductor Wastewater & Processing
• Metal Surface Finishing
• Electroplating
• Steel Industry Wastewater
• Electronics Manufacturing
• Petrochemical Processing
• Fluoride-Containing Industrial Wastewater