CASE STUDIES CONCERNING THE BAD INFLUENCE OF THE LIMIT MEASUREMENT ERROR ON CONTROL OBJECTIVITY

Abstract

When the total measurement limit error goes beyond 20% of the prescribed tolerance for the parameter to be checked here is the risk accepting some parts which reality are waste and there is the risk of rejecting some other parts which in fact are good. These risks, take place with a certain probability, according to the ration between the measurement limit error and the tolerance prescribed for the parameter to be checked. This paper make an deep analyze related to the dependence of the control uncertainty degree on the asymmetry αd of the 6σ-errors' distribution compared to tolerance.

Keywords

• Design
• uncertainty
• 6σ
• mechanical measurement
• control devices
• dynamics of machine