Method and apparatus for increasing visibility of trend lines on strip chart recorders

摘要

A multipoint recorder with a slow effective chart speed is operated to provide good visibility for the most recent record. A number of consecutive values for each point are scanned and stored. These values are recorded by a high speed printing mechanism during a first period of the recording cycle after which the chart is advanced forward for the remaining period of the recording cycle to a point which makes that record easily visible. At the end of the recording cycle the chart is retracted to start the next printing period with the printing mechanism at a point which corresponds to that required make the record look like a continuous line and to provide the desired time scale along the chart. To accomplish this the cycle time is coordinated to the chart speed and the number of consecutive scans recorded during each recording cycle.