SC11 Chart Recorder

The chart program is used to record events that change relatively slowly. It simulates plotting on a paper chart which is up to 20 screen pages wide. It displays in page mode (one screen width at a time) or as a continuous scroll. The most recent 20 pages of data are retained in memory (2 hours 46 minutes at slowest chart speed). Controls for vertical range, chart speed and bandwidth are provided. Pan and zoom controls enable any section of the plot to be examined.

The chart recorder can be used to monitor slow events. The bandwidth of the SC11/Basic AC field sensor may be extended down to 0.1 Hz to monitor the magnetic field of lifts and passing trains. True DC measurements may be made using the DC sensor with the Sensor Interface. A typical chart recorder display is shown above. It is very useful to be able to relate particular movements in the chart recording to real-world events and so it is now possible to place markers into the chart, as above, to state what and when an event was.

When charting vibration using the 731A accelerometer, an integrating filter tailored to the 731A allows direct displacement and velocity charts to be made. This is useful for “walk about” floor vibration tests at proposed electron microscope sites.

The data logging feature of the chart recorder can be used to write the results to a disc file at a specified rate, as the data is acquired. This is useful for long term recording of disturbances that occur occasionally or overnight. The adjacent screen image shows the comprehensive start and stop controls for data logging.