Gel Filled PEI Body ORP Electrode with DIN Connector for Field Applications

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

The HI3620D features a platinum sensing pin, PEI body, and a single ceramic junction.

Platinum Sensing Pin

The HI3620D ORP sensor is made with platinum. An ORP sensor must be chemically inert; it cannot be oxidized or reduced itself. It must also have the proper surface characteristics to promote rapid electron exchange, a property known as high exchange current density. Two noble metals have proven to work well for this purpose: pure platinum and pure gold are both used in the construction of ORP sensors. The platinum sensor is often preferred because it is mechanically simpler and safer to produce. Platinum can be welded to glass and has the same thermal coefficient. The platinum sensor signal is carried through the electrode body, and together with the reference signal is conducted to the measurement meter.

PEI Body

The body of the HI3620D 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.

Single Ceramic Junction

The outer junction of an electrode, also known as a salt bridge, is a 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. Other junction types are available with higher flow rates and made with different materials.

Built-In Temperature Sensor

HI3620D features a built-in thermistor temperature sensor. A thermistor temperature sensor provides for a high accuracy temperature reading.

DIN Connector

The HI3618D uses a DIN connector. This type of connector is generally proprietary to the meters they are supplied with and may not be interchangeable. Other types of connectors include BNC, screw type, T-type, and 3.5mm to name a few.