The HI36183 is a glass body, refillable, single junction ORP electrode with a built-in temperature sensor and a quick connect DIN connector. This type of connector is proprietary to specific meters such as the HI98190. The HI36183 ORP electrode features a single ceramic junction in the outer reference cell and the ORP sensing pin is made of platinum. This design consideration is ideal for laboratory and general purpose redox measurements.

The HI36183 uses a platinum pin, glass body, single ceramic junction, refillable 3.5M KCl + AgCl. 

Platinum Sensing Pin

The HI36183 ORP sensor is made of 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 called 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. Platinum sensors are usually chosen because it is mechanically simple and safe to produce. Platinum can be welded to glass and has a similar thermal coefficient.

Glass Body

A 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 rapid transfer of heat to the internal reference electrolyte. The mV generated by the reference cell is temperature dependent. The faster equilibrium is reached, the more stable the reference potential.

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 stable reading. The outer reference has a single ceramic frit. 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 have higher flow rates and are made of different materials.

Refillable

The HI36183 is a refillable probe. Since it is a single junction ORP electrode, the fill solution is HI7071 3.5M KCl + AgCl. If using a refillable ORP electrode, the fill cap should be removed prior to measurement. Removing the cap creates positive head pressure in the reference cell allowing for a higher flow rate of electrolyte through the outer junction. A higher flow rate will result in a faster and more stable reading.

Quick Connect DIN Connector

The HI36183 uses a quick connect DIN connector that makes installing and removing the probe simple and easy. This type of connector is proprietary to the meter. Please refer to the specifications table for compatible meters.