Data from the Calcium ISE can give a good indication of hardness of water (as Ca²⁺). The concentration of Calcium is also used as an endpoint indicator in EDTA-Ca/Mg hardwater titrations.

The Calcium ISE has a combination-style, non-refillable, gel-filled electrode. Like all other PVC ISE membranes, the membrane on the ISE has a limited life expectancy. However, the replaceable module of ISE allows you to simply discard the used membrane module, and replace it with a new one.

Note: We recommend that you do not purchase ISE replacement modules too far in advance of their expected time of use as degradation occurs while they are stored on the shelf.

Important: Ion-Selective Electrodes require good chemical technique and careful calibration to obtain accurate results; they are not recommended for Primary or early Seconday School students.