Sample Intervals

Not available for circular charts.

The lines drawn on the chart visualization are made up of individual data points connected by straight lines.

If the Sample Interval drop-down is set to Automatic (default view), the chart will try to show all available data points using the Sample Interval set in the instrument.

If there are more data points recorded (between the start and the end date) than there are pixels (that is, there is more than one data point in a pixel), the software shows aggregated data.

To see the same chart data but with less data points, use the Sample Interval drop-down to select a different sample (time) interval.

Note:  When large time intervals are selected a smaller subset of available data will show, which means that some transient events are not shown on the chart.

When the Sample Interval is set to 30 seconds.

  • If there is a raw data point at a 30 second sample interval, that data point is shown
  • If there is no raw data point for the 30 second sample interval, the data point shown on the chart is the value of the last known recorded raw data point

Now data points are seen at every 30 seconds, and not every 10 seconds, and the data points between the 30 second sample interval are not shown on-screen.

Data at the highest resolution possible for the width of the chart (default sample interval).

Note:  All data points on the chart visualization relate to an actual data point value. The data points are not averaged.

Note:  When a vertical cursor is placed on the chart (by clicking on the chart with the mouse), the left and right arrow keys can be used to step through the time axis at the sample interval selected.

Note:  If you select a range on the chart with two cursors, the minimum and maximum values show the true minimum and true maximum values, even though the chart may not show the extremes of the data due to only specific points being shown.

When a chart is visualized the software attempts to show all data points recorded between the start and the end date and time selection of the chart.

If there are more data points recorded, for a given time, than there are pixels there will be more than one data point in a pixel and the software will show aggregated data.

When there is more than one data point in a pixel the software calculates the time of that pixel and gives the value of the last known data point, on or preceding that time, and uses that information for the data point value in the pixel (as shown in the channel panel).

If your returned raw data is aggregated and you zoom-in on the chart, the ‘pixel to data point’ ratio changes and at some point you get to a maximum of one data point in one pixel. At this point individual data points are shown. This is shown by the addition of dots around each data point, which shows that a 1:1 visualization of data points has been reached, by zooming in enough.