Calibration of a practical haemoglobinometer.

A practical instrument for routine haemoglobinometry (HemoCue) was compared with the reference haemiglobincyanide (methaemoglobincyanide (HiCN] method. The precision of the routine method was adequate, but a systematic error of about -3.5% was found. As this resulted from errors in the procedure for coupling the haemoglobinometer read-out to the reference HiCN method, we drew up an improved calibration procedure for practical haemoglobinometers to ensure comparability of results with the reference method. After recalibration according to these rules, the HemoCue system proved to be accurate to within +/- 1.5%.