A blood gas analyzer is a medical device used to measure the levels of gases and other components in a blood sample, typically from an artery. The most common gases measured include oxygen (O2), carbon dioxide (CO2), and pH. Additionally, the device may measure electrolytes such as sodium (Na+), potassium (K+), and chloride (Cl-) ions, as well as bicarbonate (HCO3-). These measurements provide crucial information about a patient's respiratory and metabolic status.