Blood pressure (BP) measurement is the most common measurement that is made in clinical domains, and it is fundamental in diagnosing, managing, and treating hypertension. The purpose of this study is to examine if external manufacturer supplied cuffs and an internal simulator cuff could be used interchangeably, such that noninvasive BP (NIBP) monitors could be tested using solely the internal simulator cuff, hereby promoting quality assurance standardization and reproducibility. Most Omron 705IT monitors were excluded from tachycardia and obese simulations because of an excess of error readings from these monitors during these simulations. Results for Omron 705IT showed that differences between the measured value using the external cuff and the measured value using the internal cuff ranged from −1 to 2.91 mm Hg. Results for A&D UA-767Plus showed that differences between the measured value using the external cuff and the measured value using the internal cuff ranged from −1 to 3 mm Hg. This study showed that it was not possible to use external and internal cuffs interchangeably for both Omron 705IT and A&D UA767PlusBT. A variety of factors may have had an influence on measurements obtained using external and internal cuffs. These may include, but are not limited to, differing external and internal cuff hose lengths and simulator employment of proprietary and manufacturer specific algorithms. These results suggest that it is not possible to use solely the internal simulator cuff when testing NIBP monitors from these 2 manufacturers. Although research shows great promise with regard to using simulators for quality assuring NIBP monitors, there is still a lack of clarity regarding the extent to which the internal simulator cuff can be employed.