Helion 2 Pro thermal imagers are equipped with a stadiametric rangefinder which allows the user to determine the approximate distance to an object of a known size with reasonable accuracy.
Select the Stadiametric Rangefinder function with short presses of the M (9) button until the icon is selected.
You will see on the display: measurement bars, icons of three reference objects and respective distances for the three objects.
Position the lower fixed bar under the object being ranged.
By pressing the UP (10) / DOWN (8) buttons, move the upper horizontal bar relative to the lower fixed bar until the object fits entirely between the two bars. The distance to the object is automatically recalculated as you move the upper line.
Exit the rangefinder mode with a long press of the М (9) button or wait 10 seconds to exit automatically.
There are three predefined values for the reference objects: Hare - 0.3 m (1 ft.) height, Boar - 0.7 m (2.3 ft.) height, Deer - 1.7 m (5.6 ft.) height.
Before it appears on the display, a measured distance value is rounded up to 5m (16.4 ft.) for larger values and rounded down to 1m (3.3 ft.) for smaller values.
To select the unit of measurement (Meters or Yards), go to the General Settings menu item => Units of Measure submenu.