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 HI2112B uses general purpose (GP) glass, spherical bulb, and PEI body.
General Purpose Glass Formulation
General purpose glass as the name implies is a standard glass formulation that is used for general use. A pH electrode with general purpose (GP) glass will have a resistance of 100 megaohms at 25℃ and is suited for measuring pH of samples that are at ambient temperatures. The HI2112B is suitable to use with samples that measure from 0 to 70℃.
The spherical bulb is for general purpose use. Other tip shapes include conic for penetration and flat tip for surface measurements.
The body of the HI2112B 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. The PEI plastic is a high quality plastic that is chemically resistant to many aggressive chemicals.
The HI2112B 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.