This blood gas analyzer is designed for laboratory use to provide both measured and calculated parameters on both whole blood and expired gas samples. Measured parameters include pH, Sodium ion (Na+), Potassium ion (K+), and Hematocrit. Calculated parameters include Total Carbon Dioxide, base excess blood, standard Bicarbonate, Carbon Dioxide concentration, and Oxygen concentration. The IL 1640 is also equipped with an integral maintenance calendar with reminder. This software program lists the most important maintenance procedures, the date at which each maintenance operation was last performed and the maintenance frequency.