Fukuda FRE-203XR, User Manual

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HOW TO SET SLOPES (FALLS/GRADES)
Working Example 2 (when you do NOT know the grade to set)
The following description explains the general principles of setting a Slope (Fall/Grade), using the
FRE-203XR, when you do NOT know the grade to set.
Equipment
You will need the FRE-203XR laser level, its remote control, a surveying tripod, measuring staff
(rod) with mm scale and a laser detector/receiver.
Site Conditions
There are many diff erent work site scenarios. As an example, we are assuming that you are
outside, on a site with a clear fi eld of view and planning to set drainage falls.
See Diagram 1
A is a manhole cover with surveying tripod and attached FRE-203XR laser level.
B is a second manhole cover at a lower position, located the distance of “ D ” apart and by a fall of
“ F ”.
The planned sitework is to set a slope on the laser level to assist in digging a drainage channel to
join A to B .
Procedure
First measure distance “ D ”.
Next, attach the FRE-203XR on the surveying tripod, switch it ON and allow it to auto (self) level.
The tripod height is unimportant. Face keypad (Y axis) towards cover B .
Position your extended measuring staff on the ground next to the laser & clamp the detector to
pick-up the red rotating beam with a continuous tone on the detector.
Note & record the mm height from the measuring staff .
To determine & set fall F:
Before moving position from cover A , press the laser’s Manual Override button to disable the
auto (self) levelling.
Do NOT un-clamp detector. Move position and place extended measuring staff over the
centre of cover B , holding it vertically. (See diagram 2) . Un-clamp detector and move it up the
measuring staff to pick-up the laser beam with a continuous tone. (See diagram 3) Record the
new height value. The site Fall “ F ” is this value minus the value taken before at cover A .
Return the detector down to the lower position again & clamp tight. See diagram 2.
To make the next adjustment, use the remote control if distance “ D ” is less than 20m; or a
colleague at the laser, if “ D ” is more than 20m.
Hold the UP arrow button to move the laser beam down the measuring staff until a continuous
tone is heard. The laser is now set at the desired Fall.