Cardinal 2240 Operation Manual

Cardinal 2240 Operation Manual Manual pdf 32 page image

SAMPLING AND COUNT ACCURACYThis section describes certain conditions that determine the accuracy of a parts countingoperation and procedures you can follow to assure optimum performance of your DigitalCounting Scale. Accurate counts depend upon the following conditions:Functional accuracy of the scale.Individual part weight variance.Determination of parts sampling quantities.Variance of container weights in tare operations.ACCURACY OF THE SCALE (Refer to Figure No. 9)TYPICAL CONDITION ACCURACY - on a stable surface, applied load less than 70% of scalecapacity, with no air currents or vibrations present, using parts with weight variance less than1%; the total weight of all parts in the sample must be:0.2% (1/500) of scale capacity for 99.5% accuracy0.1% (1/1000) of scale capacity for 99% accuracy.WORST CASE ACCURACY - on an unstable surface, applied load near 100% of scale capacity,with air currents or vibrations present, using parts with weight variance less than 1%; the totalweight of all parts in the sample must be:0.5% (1/200) of scale capacity for 99.5% accuracyCounting accuracy will be greater than 99.5% when the total weight of all parts in the sampleexceeds 0.5% of scale capacity.31COUNT ACCURACY PERCENT0% .5% 1.0%100%99.5%99%98.5%98%97.5%WORST CASETYPICAL CONDITION% OF SAMPLEWEIGHT VS.GROSSCAPACITYFigure No. 9