This paper describes simple modifications to a demonstration Stirling engine that allows one to make quantitative measurements of the Stirling cycle. First, we describe measurements of the P-V diagram using an in-expensive pressure sensor and a common photogate. Then, as a supplement, the engine was run as a refrigerator by using a rotary tool to turn the flywheel of the engine. A small, but measurable, temperature difference developed across the body of the engine.

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