HH2100 Double-Junction pH Electrode for Fouling-Prone Wastewater

The HH2100 is a combination pH electrode designed for wastewater and contaminated process liquids containing suspended solids, deposits, or chemicals that may shorten the operating life of conventional general-purpose electrodes.

Its ring-shaped ceramic junction provides a broad contact area with the process medium. Combined with a double-junction reference system, this construction creates an additional separation barrier between the sample and internal reference element. It is designed to slow contaminant migration and reduce the likelihood of rapid reference poisoning or junction blockage.

The HA pH-sensitive membrane is formulated for general acid- and alkali-containing processes, providing full-range measurement from pH 0 to 14. The reinforced glass membrane offers added mechanical durability, although it should still be protected from direct impact, abrasive solids, and excessive installation force.

A glass body and PG13.5 process connection allow integration into compatible immersion holders, retractable assemblies, pipelines, and flow-through systems. Insertion lengths from 120 to 425 mm and several cable-connector formats are available for different installation requirements.

The HH2100 is suitable for municipal and industrial wastewater, wet gas-scrubbing liquids, semiconductor wastewater, metallurgy, mineral processing, and water-treatment equipment. Final selection should consider the complete chemical composition, solids content, abrasion, operating temperature, pressure, and required cleaning frequency.

Key benefits

• Designed for fouling-prone liquids: Ring-shaped ceramic junction provides a broad sample-contact area.
• Double-junction reference: Adds a second barrier between the process medium and internal reference element.
• HA process-glass membrane: Intended for pH measurement in general acid- and alkali-containing liquids.
• Wide operating range: Measures from pH 0 to 14 at temperatures up to 100 °C.
• Flexible process integration: PG13.5 connection fits compatible immersion, inline, and retractable holders.
• Customizable insertion depth: Available in lengths from 120 to 425 mm.
• Multiple connector options: S8, S8M, S7, VP8, K8S, and K2 configurations are available.

Configuration options

• Insertion length: Selectable from 120 to 425 mm according to the holder and required immersion depth.
• HL low-impedance membrane: Available for specific lower-conductivity water applications.
• Connector configuration: Multiple detachable cable and connector formats are available.
• 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 installation notes

For liquids containing suspended solids, install the electrode where the sample remains representative without placing the glass membrane directly in a sediment bed or high-velocity abrasive stream. Provide sufficient access for inspection and cleaning; an anti-fouling design does not make the electrode maintenance-free.

In gas-treatment applications, the HH2100 measures the pH of the liquid absorbent or scrubbing solution—it does not measure the gas phase directly.

For semiconductor wastewater, confirm the presence and concentration of fluoride or hydrofluoric acid before selection. Acid/alkali-resistant glass should not automatically be considered HF-resistant.

The 3 bar pressure rating should be checked against the actual temperature, process holder, seals, and installation arrangement, particularly near the 100 °C maximum temperature.