he 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 of the HI1144B provides a stable reference potential without the presence of silver. This design consideration is ideal for applications involving Tris buffer.
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.
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.
The spherical bulb is for general purpose use. Other tip shapes include conic for penetration and flat tip for surface measurements.
The glass body is ideal for laboratory use. The glass is resistant to many harsh chemicals and is easily cleaned. The glass body also allows for a fast transfer of heat to the internal reference electrolyte. The mV generated by the reference cell is temperature dependent. The faster the electrode reaches equilibrium, the steadier the reference potential.
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.
The HI1144B is a refillable probe. Its fill solution, HI7082 3.5M KCl, does not contain any silver. 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.
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.
| 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 |
