| 摘要 |
A method and a device for discovering and recording signal deviations that occur at long time intervals. The method comprises the steps of sensing the signal and analyzing the signal with respect to its frequency content and amplitude, monitoring the signal during a chosen initiation period in which the signal does not contain a deviation that is to be discovered and registered, forming a mean value of the signal during the initiation period and establishing an upper and a lower limit value of the signal, and sensing the signal after said initiation period and comparing the signal with said limit values and recording the signal over a pre-selected time period when one of said limit values is transgressed. The inventive device is implemented with a plug-in board in a personal computer, wherewith the board carried components are designed to carry out the method steps, such that the signal will be recorded on the hard disk of the computer in the event of a malfunction. |
