In the method of this invention, dispensed volume is calculated from the ratio of the absorbance values for a sample delivered by a precisely calibrated pipette and the sample dispensed by an automated pipette. This links a gravimetric method of calibration to a colorimetric method....http://www.google.es/patents/US5061639?utm_source=gb-gplus-sharePatente US5061639 - Liquid dispenser accuracy verification method
