Johnson Level & Tool Mfg. 40-6001 - Manual (Page 20)

20 ©2013 Johnson Level & Tool - Rev. 3
You will now see the previous Volume calculation at the top row being
added to the most recent Volume calculation in the middle row.
The sum of both Volume calculations will be displayed in the bottom row.
Follow this sequence to continue tallying additional Volume dimensions.
To subtract an Volume measurement simply press and release the
button during the sequence and that value will be deducted from the total
Indirect Measurements (Pythagorean Methods)
All Calculations are based on Pythagorean Theorem a 2 +b 2 =c 2 .
This function allows for the measurement of hard to reach jobs.
Follow the order of the flashing lines for each required measurement.
Note: For accurate measurements the instrument’s position must be held
constant. For example, note the position of your hand when
taking first measurement. Do not move your hand when preparing to take
the second measurement. Simply pivot your wrist (keeping
instrument in same position) to align the next target. Then record
next measurement.