The sum of quantitatively measured parameter values that characterize the appearance and performance of a car at a certain moment.
Inspections and measurements to determine the technical condition or work capability of the car.
Under the condition of not disassembling (or only unloading individual small parts), to determine the technical condition of the car or to find out the fault location and cause of detection, analysis and judgment
6 types of diagnostic criteria: sensitivity, uniqueness, stability, information, and economy: country, industry, locality, and enterprise.
When the same quantity is measured multiple times under the same measurement condition, the size and sign of the measurement error remain unchanged or the error changes according to a certain rule; random: when the same value is measured multiple times under the same measurement condition, the magnitude and sign of the error are irrelevant The way of foreseeing changes.