In order to make comparisons between different vessels and experimental conditions, an internal circumference that exerts a Target Pressure needs to be determined to make comparisons meaningful. The relaxed vessel wall is stretched to a number of micrometer settings for a specific size myograph. The vessel wall force in response to each stretch is recorded by using the Add Point command. After a curve is generated from these forces, the Calculate command is used to determine the internal circumference at a Target Pressure, usually 13.3kPa. The normalized internal circumference is usually determined to be 90% of this value.