482 Co-oximeter: The 482 Co-oximeter is a blood gas tester that, in addition to the condition of gas tensions provided by conventional blood gas assessments, assesses amounts of oxygenated hemoglobin (oxyHb), deoxygenated hemoglobin (deoxyHb or reduced Hb), carboxyhemoglobin (COHb), and methemoglobin (MetHb) as a percentage of the total hemoglobin accumulation in the blood sample.