A pH sensor has been improved by using a pair of glass electrodes, appropriately fitted in a suitable assembly fabricated from a polymer material. An interface has been designed and developed for processing the signal from the pH sensor. The improved pH sensor and the interface forms the improved pH sensing system. The performance of the system is good and is a cost effective solution over pH measurement errors and problems. Details of the pH sensor, interface and the results of the field trials are presented in this paper.