Adult ESL learners may not know the American measurement system. The United States is one of only five countries still using Fahrenheit to measure temperatures (see list below). Simplifying the conversion can help our learners make sense of local temperatures. The method below is “a reasonable approximation”, not an exact calculation.
In this activity, students build a basic understanding of how a sling psychrometer is used to determine relative humidity and learn how to read a chart to determine this relationship. In addition, the student will become familiar with the concept of dew point. Materials need to conduct the investigation include two thermometers, a wooden dowel, wood screw, two washers, a section of plastic straw, and a hollow shoelace. The resource includes background information, teaching tips and questions to guide student discussion. This is chapter 11 of Meteorology: An Educator's Resource for Inquiry-Based Learning for Grades 5-9. The guide includes a discussion of learning science, the use of inquiry in the classroom, instructions for making simple weather instruments, and more than 20 weather investigations ranging from teacher-centered to guided and open inquiry investigations.