Extech Instruments DT40M User Manual page 11

2. Press the
3. A parallelogram will appear with its length side flashing
4. Press MEASURE to turn Laser ON, if it is not already ON.
5. Aim the meter and press MEASURE to take the room length
measurement.
6. The parallelogram will now appear with its Width side
flashing
be taken.
7. Press MEASURE to turn Laser ON, if it is not already ON.
8. Press MEASURE to take the room width measurement.
9. Auxiliary display lines 1 and 2 will now show the Length and
Width. The primary display will show the Area (in ft
Note that the laser pointer will switch off automatically if too
much time is taken between steps. Press MEASURE to switch the
Laser pointer back ON and then try the test again.
Adding/Subtracting Area Calculations
1. After completing an Area calculation (see previous section),
with the resulsts displayed , short press the (+) key for the
'summing' mode or the (-) key for the 'difference' mode.
2. Perform another Area calculation as explained in the previous
section.
3. Press MEASURE and the display will show the change
(increased or decreased Area) from the first to the second
Area calculation in the primary display line (bottom).
key firmly once.
indicating that a Length measurement is to be taken.
indicating that a Width measurement is to
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2 2
or m ).