TEMPERATURE MEASUREMENTS IN CEMENT MANUFACTURE Portland cement is an essential ingredient for the construction industry, used to make concrete and mortar. There are more than 2,000 active cement plants around the world producing over 3.5 billion tonnes per year. They produce cement by heating crushed limestone and other ingredients in a rotary kiln to produce clinker which is milled to a fine powder to produce the finished product. Temperature monitoring in and around the kiln is essential to an efficient process, and to produce cement of consistent quality. It also enables early detection of kiln refractory issues or insufficiently quenched clinker, which could lead to production stoppages if left unchecked.