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Refillable Combination pH Electrode with BNC Connector



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Perfect for general laboratory use, the HI1131B is a glass-bodied combination pH electrode with a BNC connector for a quick and easy connection to any BNC pH meter. With a double junction design and the ability to change out contaminated electrolyte, this economical pH electrode ensures great results.

  • Easy to clean glass body for faster measurements.
  • BNC connector for quick and easy connection to most pH meters.
  • Great for general laboratory use.


Hanna Instruments offers a wide variety of pH electrodes that are designed for many different applications. The type of glass used for sensing pH, bulb shape, body material, type of junction, type of reference and electrolyte used are just some of the design considerations.

The HI1131B pH electrode uses high temperature (HT) glass, spherical bulb, glass body, a single ceramic frit, double junction and is refillable with 3.5M KCl.

ht glass

High Temperature Glass Formulation

The measurement of pH at very high temperatures is detrimental to the sensitive glass bulb and will shorten the life of it. High temperature glass can stand up to the effects of elevated temperatures leading to longer probe life.

conical tip

Spherical Glass Tip

The spherical shaped tip design allows for a wider area of contact with the sample for a faster measurement, making it ideal for general laboratory use.

glass body

Glass Body

A glass body is easy to clean, is chemically resistant, and quick to reach thermal equilibrium for a faster, more stable measurement.

single ceramic double junction

Single Ceramic Double Junction Reference

The HI1131B is a double junction design. pH electrodes are available as single junction or double junction. See below for a complete description of the differences. The junction also known as a salt bridge is necessary component of the electrical circuit. The movement of ions must flow through the junction for a steady reading. The outer reference has a single ceramic frit. The ceramic is a porous material that is easily fused with the glass body and has a similar expansion coefficient. A single ceramic junction has a flow rate of 15-20 μL/hour. Other junction types are available with higher flow rates and made with different materials.



The HI1131B is a refillable probe. Since it is a double junction combination ph electrode the fill solution is the HI7082 3.5M KCl. This solution does not contain any silver as with single junction electrode. The absence of silver will prevent any silver precipitate from forming at the junction surface and clogging it. Clogging of the junction will result in drifty and erratic readings.


BNC Connector

The HI1131B uses a BNC connector. BNC connectors allow for quick and easy connection to any pH/ORP meter or transmitter.


Body Material glass
Reference double, Ag/AgCl
Junction / Flow Rate ceramic, single / 15-20 μL/h
Electrolyte 3.5M KCl
Range pH: 0 to 13
Max Pressure 0.1 bar
Tip Shape spheric (dia: 9.5 mm)
Recommended Operating Temperature 0 to 100°C (32 to 212°F) - HT
Temperature Sensor no
Matching Pin no
Amplifier no
Digital no
Cable coaxial; 1 m (3.3’)
Connection BNC
Applications general purpose, high temperatures, laboratory general purpose
Warranty 6 months