A glass bodied reference electrode half-cell with a 12mm body.

Calomel reference electrodes require separate pH, Redox or ISEs for use. The calomel electrode is an Hg/HgCl system with a ceramic reference junction.

Please check your application as this glass bodied electrode contains a small amount of mercury which will prevent its use in direct environmental and food applications. The electrode is refillable with saturated Potassium Chloride ( KCl) filling solution.

Separate reference electrodes are superior to the reference half cells found in combination electrodes as they have a larger reservoir of filling solution and therefore a faster flow rate of electrolyte through the junction which provides faster response and greater stability.

The EDT Calomel electrodes have several advantages over the Ag/AgCl alternatives. Firstly they provide a longer lifetime as the internal solution does not contain Silver Chloride which, in certain applications, and particularly in acid conditions deposits in the reference junction. This reduces flow rate and eventually causes blockage. Silver Chloride references are also prone to greater instability when the internal solution is contaminated by back diffusion of the sample. A good example of this is with the use of TRIS buffers which should be measured using Calomel references.

Care should be taken to ensure you comply with environmental legislation with when disposing of used Calomel electrodes.The Calomel reference comes with a 4mm connector and is compatible with all types of pH electrode. Calibration is usually made between two buffer solutions.

To view a simple calibration click here.