HH2800P Pure Water Online Process pH Electrode for High-Temperature & High-Pressure| Glass Body Electrodes | PTFE Double Junction

The HH2800P is a combination pH electrode designed for high-temperature, low-conductivity water. It extends the high-purity-water configuration of the HH2300P to applications requiring operation at temperatures up to 130 °C and pressures up to 6 bar, subject to the product’s pressure-temperature limits.

Its HSL ultra-low-impedance glass membrane has a specified resistance below 50 MΩ. This lower electrical resistance supports responsive signal stabilization in water with conductivity from 0.5 to 100 μS/cm when used with a compatible high-input-impedance pH transmitter.

The annular PTFE junction provides a broad contact area between the reference electrolyte and sample. A low-viscosity SRG polymer-gel electrolyte supports ionic contact at elevated temperatures, while the double-junction reference system adds another separation barrier between the process and internal reference element.

The HH2800P uses a PG13.5 process connection and is available in insertion lengths from 120 to 425 mm. Multiple connector and integrated temperature-sensor options allow integration into compatible flow-through chambers, immersion holders, retractable assemblies, and sample-conditioning systems.

Typical applications include high-temperature, high-purity water and conditioned water samples in power-generation and industrial boiler systems. The electrode’s 6 bar maximum pressure does not make it suitable for direct installation in boiler drums or other process points operating above that pressure.

Key benefits

• Designed for high-purity water: Recommended for water with conductivity from 0.5 to 100 μS/cm.
• High-temperature operation: Specified for compatible process water at temperatures up to 130 °C.
• HSL ultra-low-impedance membrane: Membrane resistance below 50 MΩ supports responsive signal stabilization.
• Annular PTFE junction: Provides a broad ionic contact area with the sample.
• Low-viscosity SRG electrolyte: Configured for reference-system operation in elevated-temperature water.
• Double-junction reference: Adds a second barrier between the sample and internal reference element.
• Flexible process integration: PG13.5 connection with customizable insertion lengths and connector options.

Configuration options

• Insertion length: Selectable from 120 to 425 mm according to the process holder and required immersion depth.
• HC general-purpose membrane: Available for higher-conductivity water where an HSL membrane is not required.
• Connector configuration: Multiple detachable cable and connector formats are available.
• Extended cable: Cable lengths up to 60 metres, subject to transmitter compatibility and electrical conditions.
• Integrated temperature sensor: Selectable NTC, Pt100, and Pt1000 options.
• Measurement assembly: Flow chamber, holder, seals, and fittings should be selected for the required purity, temperature, pressure, and flow conditions.

High-purity water measurement notes

High-purity water pH is sensitive to flow, static charge, grounding, liquid-junction potential, pressure variation, air ingress, and carbon-dioxide absorption. Stable online measurement therefore depends on the complete sampling and electrical system, not only the electrode.

Where practical, use a closed, continuous-flow sample line with stable flow, temperature, and pressure. Avoid stagnant samples, gas bubbles, negative pressure, excessive backpressure, and unnecessary atmospheric exposure.

Automatic temperature compensation corrects the temperature-dependent electrode slope. It does not necessarily convert the sample to the pH it would have at 25 °C because the water’s actual chemical equilibrium also changes with temperature.

Power-station samples are commonly cooled and pressure-conditioned before pH measurement. Direct high-temperature installation should only be used where the process pressure is within the complete assembly rating and the measurement objective requires in-situ operation.

The HH2800P’s stated lower conductivity limit is 0.5 μS/cm. It should not be described as suitable for semiconductor-grade ultrapure water near 0.055 μS/cm unless separate testing confirms that application.

Application

• High-Purity Water
• High-Temperature Water Systems
• Power Generation & Steam-Water Cycle
• Industrial Boiler Water
• Boiler Feedwater Treatment
• OEM Water-Treatment & Sample-Conditioning Systems