Calcium Ion-Selective Electrode

Product image for Calcium Ion-Selective Electrode

The Calcium Ion-Selective Electrode (ISE) can be used to measure the concentration of Calcium (Ca2+) in aqueous samples.


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 middle school or elementary students.



  • Interfering Ions: Pb2+, Hg2+, Sr2+, Cu2+, Ni2+, NH3, Na+, L1+, K+, Ba2+, Zn2+, Mg2+
  • pH Range: 2 to 8
  • Temperature range: 0 to 40°C
  • Electrode Slope: +26 mV
  • Electrode Resistance: 100 MΩ
  • Immersion: 2.8 cm (1.1 in)

Download the user manual for full specifications

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What’s Included

  • Vernier Calcium Ion-Selective Electrode
  • 30 mL bottle of Calcium Low Standard (10 mg/L)
  • 30 mL bottle of Calcium High Standard (1000 mg/L)
  • Short-term ISE soaking bottle
  • User manual

Sensor Requirements

The Calcium Ion-Selective Electrode requires a compatible interface and software to collect data. Interface and software sold separately. Getting started with probeware »

Compatible Interfaces

The Calcium Ion-Selective Electrode is compatible with these interfaces:

Ordering Information

All prices are for U.S. educators.

NameOrder CodePriceQuantity
Calcium Ion-Selective ElectrodeCA-BTA$179
Optional Accessories
Electrode SupportESUP$10

Related Products

Educational use only: Vernier products are designed for educational use. They are not appropriate for industrial, medical, or commercial applications. Product usage disclaimer »

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