Working Advice - Berner BLM 80 Manual Original

To call up the sum of both meas-
urements, press the result button
6. The calculation is indicated in
the measured-value lines a, and
the sum in the result line c.
After calculation of the sum, further measured val-
ues or measured-value list entries can be added to
this result when pressing the plus button 11 prior
to each measurement. Pressing the result button 6
ends the addition.
Notes on the addition:
– Mixed length, area and volume values cannot be
added together. For example, when a length and
area value are added, "ERROR" briefly appears
on the display after pressing the result button 6.
Afterwards, the measuring tool switches back to
the last active measuring mode.
– For each calculation, the result of one measure-
ment is added (e.g. the volume value); for con-
tinuous measurements, this would be the dis-
played measured value in result line c. The
addition of individual measured values from the
measured-value lines a is not possible.
Subtracting Measured Values
To subtract measuring values,
press minus button 5; For confir-
mation, " – " is indicated on the dis-
play. The further procedure is
analog to "Adding Measured Val-
ues".

Working Advice

General Information
The reception lens 17 and the laser beam outlet 16
must not be covered when taking a measurement.
The measuring tool must not be moved while tak-
ing a measurement (with the exception of the con-
tinuous measurement and grade measurement
functions). Therefore, place the measuring tool, as
far as this is possible, against or on a firm stop or
supporting surface.
Influence Effects on the Measuring Range
The measuring range depends upon the light con-
ditions and the reflection properties of the target
surface. For improved visibility of the laser beam
when working outdoors and when the sunlight is in-
tense, use laser viewing glasses and laser target
plate, or shade off the target surface.
Influence Effects on the Measuring Result
Due to physical effects, faulty measurements can-
not be excluded when measuring on different sur-
faces. Included here are:
– Transparent surfaces (e.g., glass, water),
– Reflecting surfaces (e.g., polished metal, glass),
– Porous surfaces (e.g. insulation materials),
24 | English
– Structured surfaces (e.g., roughcast, natural
stone).
If required, use a laser target plate on these surfac-
es.
Furthermore, faulty measurements are also possi-
ble when sighting inclined target surfaces.
Also, air layers with varying temperatures or indi-
rectly received reflections can affect the measured
value.
Accuracy Check and Calibration of the Grade
Measurement (see figure H)
Regularly check the accuracy of the grade meas-
urement. This is done by carrying out a reversal
measurement. For this, place the measuring tool
on a table and measure the grade. Turn the meas-
uring tool by 180 ° and measure the grade again.
The difference of the indicated reading may not ex-
ceed by more than 0.3 ° (max.).
In case of greater deviation, the measuring tool
must be recalibrated. For this, press and hold the
grade measurement button 3. Follow the directions
on the display.
Accuracy Check of the Distance Measurement
The accuracy of the distance measurement can be
checked as follows:
– Select a permanently unchangeable measuring
section with a length of approx. 1 to 10 metres;
its length must be precisely known (e.g. the
width of a room or a door opening). The measur-
ing distance must be indoors; the target surface
for the measurement must be smooth and reflect
well.
– Measure the distance 10 times after another.
The deviation of the individual measurements from
the mean value must not exceed ± 2 mm (max.).
Log the measurements, so that you can compare
their accuracy at a later point of time.
Working with the Tripod
The use of a tripod is particularly necessary for
larger distances. The measuring tool can be
screwed onto a commercially available tripod using
the 1/4" thread 19 on the bottom side of the hous-
ing.
Set the corresponding reference level for measure-
ment with a tripod by pushing button 10 (the refer-
ence level is the thread).
Working with the Measuring Rail
(see figures I–K)
The measuring rail 24 can be used for a more ac-
curate grade measurement result. Distance meas-
urements are not possible with the measuring rail.
Place the measuring tool into the
measuring rail 24 as shown and
lock the measuring tool with lock-
ing lever 25. Press the measuring
button 2 to activate the "Measuring
rail" operating mode.
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