ST270 Starter pH ElectrodeOHAUS Precision Powers the Starter Electrodes The ST270 Starter pH electrode is ideal for pH measurement in semi solid applications, where puncturing the sample may be required. Backed by our commitment to accurate and precise measurement, the OHAUS Starter Series of electrodes are designed to produce exact results time and time again. The Starter Series includes pH, reference, oxidation reduction potential (ORP), conductivity, dissolved oxygen (DO),