Patent ID: 7149639
Filing Date: 2006-12-12
Classification: G01N

Abstract:
1. A method of detecting clogging of a nozzle used for aspirating and dispensing aliquot volumes of a sample, comprising the steps of: preparing an aspiration program consisting of threshold pressure values and corresponding plural discrete aspiration volumes depending on a sample to be dispensed wherein sensitivity at which clogging is detected is switched between plural values by setting plural threshold values for each aspiration volume, and wherein the threshold values corresponding to the aspiration volumes of sample are found for each of said plural values of the sensitivity; driving an aspiration pump to draw the sample according to the program; measuring the pressure inside the nozzle; and comparing the measured pressure with threshold values which correspond to aspiration volumes of sample and which are calculated by a method of interpolation from plural threshold values set for plural discrete aspiration volumes, to detect whether the nozzle is clogged or not and indicating the result.