User's Manual

Incline the laser as described at 7.5.2, but in alignment
with the inclined plane.
7.6.4 Optional electronic alignment
After setting the slope as described above, alignment
of the PR 35 can be optimized by Hilti’s patented
electronic alignment system.
1. Position the PRA 35 centrally opposite the PR 35
at the end of the inclined plane. It can be held
still by hand or fixed in place with the aid of the
PRA 80.
2. Switch the PRA 35 on.
3. Activate electronic alignment on the PR 35 by
pressing the “Left” arrow button.
4. If the shock warning / slope LEDs blink, the
PRA 35 is not receiving the laser beam from the
PR 35.
5. If the shock warning / monitoring LEDs blink,
realign the PR 35 by moving it counterclockwise.
6. If the slope / monitoring LEDs blink, realign the
PR 35 by moving it clockwise.
7. If the monitoring LED blinks, alignment is correct.
8. End electronic alignment mode by pressing the
“Right” arrow button.
7.6.5 Setting the slope with the aid of the
PRA 76/78 slope adapter
NOTE
Check that the slope adapter is fitted correctly between
the tripod and the tool (please refer to the operating
instructions).
7.7 Monitoring
The monitoring function checks at regular intervals
whether the plane that is set (vertical, horizontal
or inclined) has been altered inadvertently (e.g. by
vibration). If this is the case, the projected plane
will be realigned to the zero point (i.e. the marking
notch on the PRA 35) (so long as it is still within the
receiving area). A PRA 35 is required for use of the
monitoring function. An additional laser receiver can
be used to detect the laser beam while the laser beam
is being monitored.
1. Preparation for activation of the monitoring func-
tion is basically the same as the procedure for
activation of automatic alignment mode.
2. Position the tool at the desired starting point 1
and switch it on.
3. Position PRA 35 laser receiver at the reference
point (point 2) on the axis and secure it there.
The PRA 751 can be used to secure it. The tool
(point 1) and the PRA 35 (point 2) then form
anchor points on the plane. Take care to ensure
that the marking notch on the PRA 35 is at exactly
the height at which the rotating laser is later
to project the laser line or point. The red laser
receiving surface on the PRA 35 must face the
rotating laser.
4. Take care to ensure there are no obstructions
between the rotating laser and the PRA 35 laser re-
ceiver which could interfere with communication
between the devices. Glass and other translucent
materials may also interfere with communication
between the devices. Reflections from windows
may also cause interference.
5. Switch the PR 35 and the PRA 35 on. The mon-
itoring function can be activated by pressing the
“Monitoring mode” button on the PRA 35.
6. The system is then in monitoring mode. The
function is indicated in the display on the PRA 35
by two regularly blinking arrows pointing toward
the axis in which alignment is to be carried out.
7. The monitoring system checks at regular intervals
whether the laser plane has shifted. If it is found
to have shifted, the laser plane will be readjusted
to the original marking plane as far as possible.
If the marking plane is outside the self-levelling
range (10° (±5°)) or the line of sight between the
rotating laser and the laser receiver is blocked
for a certain length of time, an error message is
displayed.
7.8 Returning to standard mode
In order to return to standard mode, horizontal align-
ment, 300 /min, the tool must be switched off and
restarted.
7.9 Sleep mode
The PR 35 saves power when in sleep mode. The
laser is switched off, thereby extending battery life.
Activate sleep mode by pressing the “Sleep mode”
button on the PRA 35.
Deactivate sleep mode by pressing the “Sleep mode”
button on the PRA 35 again.
After reactivating the PR 35, check the laser settings
in order to ensure accuracy.
en
13