FC2153 is a glass body, refillable single junction pH electrode with a quick connect DIN connector. This electrode features a triple ceramic junction in the outer reference cell and the pH sensing bulb is made of low temperature glass.

FC2153 uses low temperature (LT) glass, spherical bulb, glass body, triple ceramic junction, refillable with 3.5M KCl + AgCl.

Low Temperature Glass Formulation

Measuring the pH of a solution at low temperatures can be difficult due to the effect temperature has on the resistance of the glass membrane. Standard pH electrodes use general purpose (GP) glass that has a resistance of 100 megohms at 25°C. This resistance will increase as the temperature decreases. If the resistance increases above the normal range, the measurement will be affected. Some pH electrodes use low temperature (LT) glass as the pH sensitive glass membrane. LT glass has a resistance of about 50 megohms at 25°C. As the temperature of the glass decreases, the resistance of the LT glass approaches that of GP glass. The FC2153 is made of LT glass and is suitable for samples from 0 to 70°C.

Spherical Bulb

The spherical bulb is used for general purpose. Other shapes include conical for penetration and flat for surface measurements.

Glass Body

A glass body is ideal for laboratory use. The glass is resistant to many harsh chemicals and is easy to clean. 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 equilibrium is reached, the more stable the reference potential.

Triple Ceramic Junction

The triple ceramic junction allows a faster flow rate of electrolyte from the reference cell into the solution. A standard pH electrode will use a single ceramic junction that allows for 15 to 20 μL/hr of electrolyte flow; the FC2153 has three ceramic junctions providing for 40 to 50 μL/hr of electrolyte flow. This high flow rate provides for a faster electrode response and a more stable measurement in low conductivity samples such as drinking water.

Refillable

The FC2153 is a refillable probe. It is a single junction pH electrode that uses HI7071 3.5M KCl + AgCl electrolyte fill solution. If using a refillable pH electrode, the fill cap should be loosened/removed prior to calibration and measurement. Loosening/removing the cap creates a positive head pressure in the reference cell that increases the flow rate of electrolyte through the outer junction. A higher flow rate will result in a faster and more stable reading.