# What are the different parts of a blood pressure apparatus?

The three types of blood pressure machines are Automatic Sphygmomanometer, Aneroid Sphygmomanometer, and Mercury Sphygmomanometer. The automatic performs automatic functions such as cuff inflation and sophisticated readings. The aneroid consists of a metal bellows that expands on account of increased pressure so the amplifier effects the indicator needle. The mercury is dependent upon the other blood pressure machines for accuracy and calibration.