The AVL 995-Hb measures carbon dioxide partial pressure, oxygen partial pressure, hydrogen ion concentration expressed as pH and hemoglobin in whole blood. The AVL 995-Hb also measures gas partial pressures in expired gas. The AVL 984-S determines sodium, potassium and ionized calcium in whole blood, serum, dialysate fluids and urine. The two instruments work independently of each other and require individual sample input. However they can be interfaced electronically so that patient results from the 984-S are transmitted to the 995-Hb for printing on a combined blood gas and electrolyte report. Hydrogen ion concentration, electrolytes and blood gas partial pressures are measured using electrode technology. Hemoglobin is quantified by measurement of the absorbance of a haemolysate at 546 nm. Thirteen other parameters are derived mathematically from the measured parameters.

The measurement of all the available analytes was evaluated. Whole blood samples were used for blood gas, pH and hemoglobin assessment and whole blood and plasma samples for sodium and potassium; calcium measurement was assessed using quality control material only. The evaluation included assessment of the analytical performance, carryover, ease of use, safety and reliability of the analyzer.

Adjustments can be made to the instrument''''s calibration to enable satisfactory correlation with other instrumentation. Instrument maintenance was straightforward.