button. A horizontal measurement, a vertical measurement, or both may be drawn.You may draw measurements on a chart by marking a region with the mouse, then clicking the button. A horizontal measurement, a vertical measurement, or both may be drawn.
The horizontal measurement shows the distance between the left and right sides of the marked region. The distance is reported in minor location units (feet or meters), and is the actual measured distance between the points, not the scaled distance. A distance measurement drawn on a "long mile" will be longer than the interval marked on the chart scale. For example, if the actual distance between MP 37 and MP 38 is 1.1 miles, the electronic ruler will show a distance of 581 feet between two points separated by 0.1 "scaled" mile.
The vertical measurement shows the difference on the primary Y axis of the chart. A vertical measurement may not be drawn across more than one chart.
To erase measurements drawn by the electronic ruler, either click the Ruler button again without marking a rectangle, or display a new chart page.