This pH combination electrode is made of sensitive glass membrane with low impedance.It can be used in a variety of PH measurements with fast response, good thermal stability.It has the good reproducibility, difficult to hydrolysis, and basically eliminate the alkali error .In 0 to 14pH range,the output voltage of the electrode is linear.The reference system which consist of the Ag/AgCl gel electrolyte salt bridge has a stable half-cell potential and excellent anti-pollution performance.The ring PTFE membrane is not easy to be clogged, so the electrode is suitable for long-term online detection