DUI Metrology Dictionary
Precision (in the context of the Intoxilyzer)
VIM 2.15" closeness of agreement between indications or measured quantity values obtained by replicate measurements on the same or similar objects under specified conditions." Think of 3 darts or arrows clustered together, close to each other but far from the target. They are precise but not accurate. Ideally you want both accuracy and precision. The manufacturer of the Intoxilyzer 8000C advertises specifications of precision of less than 3.0. VIM 2.15 says: "NOTE 1 Measurement precision is usually expressed numerically by measures of imprecision, such as standard deviation, variance, or coefficient of variation under the specified conditions of measurement."