What is the procedure for measuring arterial pressure?

The user must have been at rest for the last 20 minutes and not be nervous.
The user must be sitting with the arm extended and comfortably supported on a surface.
The cuff should be rolled up on one of the arms above the elbow flexure, ensuring that the center of the chamber (or the cuff mark) coincides with the brachial artery and that the lower edge of the cuff is 3 cm above the antecubital fossa.
The cuff should be inflated about 20 mm Hg above the point at which the brachial pulse is no longer palpable.
The phase I of Korotkoff should be used for the systolic blood pressure and the V (disappearance) for the diastolic blood pressure.
The blood pressure measurement should be taken three times in a sitting position, separated by at least two minutes, discarding the first and averaging the last two.