This study aimed to develop teaching materials for an automatic dimension measurement system for learning　the measurement and control of a pneumatic cylinder with a length measurement function and evaluate the performance of this system from an instructor’s perspective. The proposed system automatically measures the height of a beverage can while pressing a lever attached to the piston rod of a pneumatic cylinder that can detect the displacement of the piston rod using an encoder via pneumatic control. First, the author confirmed the performance of this system, i.e., sorting beverage cans of different heights. Next, the author evaluated the present system as teaching materials in practical training in terms of wiring, operation, and assessment of the pneumatic cylinder with a length measurement function from an instructor’s perspective. The evaluation results indicated that the teaching materials would arouse interest in practical training and result in an experiential acquisition of the knowledge of automation technology for a system that sorts workpieces with different heights, thus suggesting the utility of the proposed system as teaching materials.