Refillable PEI Body pH Electrode w/Screw Cap

The HI1312S is a PEI body, double junction pH electrode with a screw cap connector. This electrode has a single ceramic junction in the outer reference cell and the pH sensing portion is made with general purpose glass, protected by an extension of the durable PEI body. This design consideration is ideal for chemicals, quality control, field applications, and general purpose use.

Durable PEI Body
Double Junction Design
Refillable Electrode

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 HI1312S uses general purpose (GP) glass, spherical bulb, polyetherimide (PEI) body, single ceramic frit, and double junction.

General Purpose 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 LT glass is around 50 megaohms at 25°C. As the temperature of the glass decreases in the sample, the resistance of the LT glass will approach that of GP glass. If using GP glass, the resistance would increase above the optimum range, resulting in increased impedance and ultimately affecting the measurement. The HI1312S is suitable to use with samples that measure from 0 to 70°C.

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

PEI Body
The body of the HI1312S is composed of polyetherimide (PEI) resin. The PEI body is suitable for a wide range of applications and excels in field measurements due to its durability. The shielding around the spherical glass tip minimizes breakage due to accidental bumping or dropping of the electrode. PEI plastic is a high-quality plastic that is chemically resistant to many aggressive chemicals.

Double Junction Reference
A double junction electrode has an internal compartment surrounding the reference wire. Silver ions are present in the electrolyte of the internal compartment, which houses the Ag/AgCl reference wire; the electrolyte outside this compartment is silver free. The double junction design means that virtually no silver from the electrode enters the sample. This design allows measurement in applications where silver ions in the sample are undesirable or silver precipitates on the junction are likely to form.

Screw Cap Connector
The HI1312S uses a screw connector. Screw connectors attach directly to the meter and can also be made interchangeable with other meters by using a Hanna BNC extension cables.