Potassium Ion-Selective Electrode

Product image for Potassium Ion-Selective Electrode

The Potassium Ion-Selective Electrode can be used to measure the concentration of potassium (K+) ions in aqueous solutions.


The Potassium Ion-Selective Electrode makes the measure of potassium ions portable. When used with a Vernier LabQuest 2, the Potassium ISE can be used to take readings in the field – at lakes or streams. This sensor is easier to set up and use than other methods of measuring potassium ion concentration in aqueous solutions. Because it is a stick-style sensor, its use is similar to using a conductivity probe or a pH sensor in a laboratory setting or in the field.

Ion-Selective Electrodes require good chemical technique and careful calibration to obtain accurate results. They are not recommended for middle school or elementary students.

We recommend that you do not purchase Potassium Ion-Selective Electrode replacement modules too far in advance of their expected time of use; degradation occurs while replacement modules are stored on the shelf.



  • Range: 90 – 39,000 mg/L (or parts per million)
  • pH range: 2 – 12
  • Temperature Range: 0 – 40°C (not compensated)
  • Interfering Ions: Rb2+, Cs2+, NH4+, Ca2+, Mg2+, Li+
  • Electrode Resistance: >50 mΩ
  • Electrode Slope: 56 +/- 4 mV/decade at 25°C
  • Calibration Voltage (typical): 2.7 V (1000 ppm), 1.9 V (10 ppm)
  • Reproducibility (precision): +/- 11% of full scale
  • Minimum sample size: 3 mL in a 50 mL beaker
  • Accuracy: +/- 16% of full scale

Download the user manual for full specifications


Preview and/or edit the potassium experiments for your curriculum by downloading the experiments below. The Computer and LabQuest downloads includes objectives, materials, procedures, and analysis. The Instructor download includes notes, sample results and graphs, and answers.

Experiment Download
1 Potassium in Commercial Products Computer LabQuest Instructor
2 Potassium in Foods Computer LabQuest Instructor

What’s Included

  • Vernier Potassium Ion-Selective Electrode
  • 30 mL bottle of High Standard Standard (1000 mg/L)
  • 30 mL bottle of Low Standard Standard (10 mg/L)
  • ISE soaking bottle (empty bottle with insertion cap)
  • User manual

Sensor Requirements

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

Compatible Interfaces

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

Software Requirements

The Potassium Ion-Selective Electrode requires data-collection software:

Ordering Information

All prices are for U.S. educators.

NameOrder CodePriceQuantity
Potassium Ion-Selective ElectrodeK-BTA$179

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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