Esophageal pH monitoring developed a dependable external reference electrode. Using this technique to monitor esophageal acid exposure patients for periods up to 24 hours, DeMeester and Johnson were able to identify the most important parameters of esophageal acid exposure, and they developed a composite pH score to quantify gastroesophageal reflux. The initial 24-hour pH studies required hospitalization until the introduction of microcircuits in the 1980s that allowed portable esophageal pH monitoring in an outpatient setting. Gastroesophageal reflux disease (GERD) is a common disease in western countries. In the United States, 7% of the population experiences heartburn daily and 44% at least once a
Dealkalization dealkalized containers tend to yield a pH that remains approximately neutral. A much more thorough version of this test is outlined in various international and domestic testing standards for glass containers, all with comparable methodologies. These tests evaluate the hydrolytic stability of the containers under more severe conditions, wherein containers, filled close to capacity with purified water, are covered and then heat-cycled in an autoclave at 121 °C for 1 hour. After cooling to room temperature, the water is titrated with acid to evaluate the pH of the water, and therefore the equivalent amount of alkali extracted during the heat