The reference electrode/salt bridge combination allows the measurement of pH or redox in those cases when:
Excessive contamination of the reference diaphragm or poisoning of the reference system is expected. The flow of the reference liquid through the diaphragm is increased by pressuring the container. The distance to the reference system is increased. Consequently, the contamination rate will decrease.
The process can not be contaminated with KCl. The salt bridge can be filled with several types of electrolytes.
Measurement has to be performed at processes up to 1,000 kPa (10 bar) and temperatures up to 100° C. As the reference electrode is mounted in the container and therefore in more favorable conditions, the lifetime will be extended reasonably. The container with reference liquid can be pressurized.