HANNA HI1144B Refillable Combination pH Electrode

HANNA HI1144B Refillable Combination pH Electrode with Calomel References

The HI1144B is a glass body, refillable, single junction pH electrode with a BNC connector. This electrode has a single ceramic junction in the outer reference cell and the spherical pH sensing portion is made with high temperature glass. The mercury/mercury (I) chloride (Hg/Hg2Cl2) reference system provides a stable reference potential without the presence of silver. This design consideration is ideal for applications involving tris buffer.

Calomel reference

Refillable

High temperature glass

Details

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 HI1144B uses high temperature (HT) glass, spherical bulb, glass body, single ceramic frit, single junction and is refillable with 3.5M KCl.

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. A pH electrode with general purpose (GP) glass will have a resistance of 100 megaohms at 25°C while the resistance of HT glass is around 400 megaohms at 25°C. As the HI1144B is used at elevated temperatures the resistance decreases to approach the that of GP glass. The HI1144B is suitable to use with samples that measure from 0 to 100°C.

Spherical Bulb

The spherical bulb is for general purpose use. Other tip shapes include conic for penetration and flat tip for surface measurements. 

Glass Body

The glass body is ideal for laboratory use. The glass is resistant to many harsh chemicals and is easily cleaned. The glass body also allow for a fast transfer of heat to the internal reference electrolyte. The mV generated by the reference cell is temperature dependent. The faster the equilibrium the steadier the reference potential.

Single Ceramic Outer Junction

The HI1144B is a single junction design. 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.  

Refillable

The HI1144B is a refillable probe. Since it is a double junction 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 HI1144B uses a BNC connector. This type of connector is universal in that it can be used on any pH meter that has the female BNC probe input. Other type of connectors include DIN, screw type, T-type, and 3.5mm to name a few. These types of connectors tend to be proprietary for a particular type of meter and are not interchangeable.

Specifications

Body Material	glass
Reference	single, Hg/Hg₂Cl₂
Junction / Flow Rate	ceramic, single / 15-20 μL/h
Electrolyte	3.5M KCl
Range	pH: 0 to 14
Max Pressure	0.1 bar
Tip Shape	spheric (dia: 9.5 mm)
Diameter	12 mm
Body Length / Overall Length	120 mm / 175.5 mm
Recommended Operating Temperature	0 to 60°C (32 to 140°F) - HT
Temperature Sensor	no
Matching Pin	no
Amplifier	no
Digital	no
Cable	coaxial; 1 m (3.3’)
Connection	BNC
Applications	tris buffer