Recording devices

The author calls attention to the importance of keeping records in electrical systems and points out that proper records can be secured only by automatic recording devices largely because of the uncertainty of the personal element in times of accident or stress. The three types of recording devices in general use are those having a revolving disk, those using an endless tape or photo-film, and multi-recording device on which no record is made of normal operations and on which the record sheet moves only when a record of abnormal occurrences is being made. The revolving disk machines produce such condensed records that a sequence of rapidly fluctuating events cannot be distinguished, while the curve drawing instruments, if the tapes were run rapidly enough to show all the fluctuations, would produce records of such enormous length that they would be impracticable to operate commercially. With the multi-recorder the record is made in a very condensed and handy form and its accuracy in respect to time is very high, so that the sequence of events recorded can be checked within a fraction of a second. The latter instrument, therefore, is adapted to produce minute and accurate records of all phases of station operation.