Electrodes we offer are mostly combination pH electrodes. Combination electrodes contain both half cells—the sensing and reference half-cell—in one single probe. We also offer the traditional sensing and reference half-cells. The best option will depend on the type of samples you will measure. pH Laboratory and Industrial pH electrodes are available in a wide variety of options appropriate for general purpose or specialty applications. In fact, we offer one of the largest selections of industrial pH and Oxidation Reduction Potential (ORP) electrodes for your applications.