The measurement of aerial pressure using a sphygmomanometer bag with a standard arm cuff is subject to inaccuracy leading to falsely high aerial pressure readings. Using sphygmomanometer blood flow is detected. The accuracy of blood pressure measurement is affected by the cuff size. Inadequate cuff size result in falsely elevated blood pressure reading. A large cuff size result in falsely low reading. Ref: Medicine for Anaesthetists By Michael Douglas Vickers, Ian Power, Ppage 285; Critical Care Study Guide: Text and Review By Gerard J. Criner, Page 157.