Показатель концентрации ионов водорода рН есть мера активности этих ионов в растворах. Зависимость громадного количества химических, биохимических, природных, технологических и многих других процессов от величины рН стимулирует развитие теории и техники измерения этого показателя. Рассмотрено современное состояние способов измерения рН. Трудно отыскать такую область науки, технологии и химии ра...

In a recent investigation1 a procedure was found that permitted fairly accurate determinations of the pH of soils of low moisture percentages. One of the essentials of the method was the use of a horn spoon in spreading the moisture or soil films uniformly throughout the rather dry soil mass. When plant tissue is finely cut in a grinder, relatively few of the cells are actually opened. The impo...

If we are to monitor the chemical processes in cementitious materials, then pH assays in the pore solutions of cement pastes, mortars, and concretes are of key importance. However, there is no standard method that regulates the sample-preparation method for pH determination. The state-of-the-art of different methods for pH determination in cementitious materials is presented in this paper and t...