Time Series Graphs
Georeferenced time-history charts may be used to show the change in concentration of multiple constituents over time. Options include multiple axes, trend-lines, and presentation of regulatory standards.
Time Axis Tab
•Date From / To
•Interval - select interval for time-axis labels
Left / Right Axis Tabs
•Interval - Specify the interval between labels on the vertical axis (when log scale is chosen, the interval is integral powers of 10 (0.01, 0.1, etc.))
•Digits Right of Decimal - Select the number of digits right of the decimal shown on the vertical axis
•Log Scale - Check to plot using a log scale
•Scientific Notation - Check to post values on axis using scientific notation
Max. Gap to Plot Line (days) - indicate the maximum inter-value gap in days for which connecting line will be drawn. If the gap between two points exceeds that duration then no line will be drawn.
EnviroInsite uses the Sen Slope method described in EPA/240/B-06/003 for plotting of trend lines. The Sen Slope is a non-parametric method calculated as the median of the slope between all measurement pairs. The trend line is set to pass through a point set to the median of the sample dates and the median of the plotted values.