Development Of An Interactive Psychrometric Chart Tutorial

The psychrometric chart may be a troublesome tool for undergraduate students to learn to use. The chart’s importance in the analysis of industrial systems involving air and water vapor is undeniable, and reading the chart is an important skill for students to master. The tutorial presented in this paper is an interactive, online supplement to textbook explanations of the chart. Sophomore students in an “Introduction to Process Engineering Calculations” course used the tutorial as their first exposure to the material, and upper division students in a “Mass Transfer Operations” course used the tutorial as a review/refresher on the chart prior to their study of humidification and drying processes. Student reaction to the tutorial was overwhelmingly positive; the tutorial allowed students to spend as much (or as little) time as they needed to master the use of the chart. Use of the tutorial as an out-of-class assignment has eliminated the need to use class time to teach the basic skills of reading properties from the chart, and allowed greater emphasis on use of the chart in problemsolving. Introduction Over many years of teaching the “Introduction to Process Engineering Calculations” course, I developed a set of standard lectures and activities to introduce students to the psychrometric chart. These activities consumed at least two hours of class time. During this time, most students could gain at least a basic understanding of the chart. Other students were still clearly baffled, while still others picked up the material quickly and became bored. My goal in the creation of an online tutorial for this material was to translate my teaching techniques into a web application that would allow students to work with the tutorial as much (or as little) as necessary for them to master the material. I would then be able to concentrate my in-class activities on problemsolving techniques using the physical properties from the chart. Even though there are widely available psychrometric calculators on the internet (e.g. Linric, 2001), I believe that the physical understanding of the air/water vapor system imparted by learning to read the chart is a valuable part of a process engineer’s toolbox. Tutorial Development The development of the tutorial began during the summer of 2003. The UW-Stevens Point Information Technology (IT) group had an interest in working with faculty to develop “learning objects”, which can be defined as small, reusable “chunks” of course content (Wiley, 2000). I