Calculated Industries 6414 - Manual (Page 19)

Taking Wall-to-Wall Measurements
Unlike other measuring wheels, the DigiRoller/DigiRoller Plus
has a built-in function which enables you to measure true
wall-to-wall distances (taking into account the wheel’s radius
when measuring up to a wall). The wheel radius key
[+D]
will add the radius of the wheel to the measurement.
To measure a room accurately, press the wheel radius key
whenever your measurements begin or end against one wall.
When you press this key, the DigiRoller will add distance to
the measurement. Depending on your selected wheel size and
measurement units, the first and second presses of this key
may not appear to be adding equal distances. However, this is
a display value only; internal calculations will be accurate.
17 – User’s Guide