David White LT8-300 - Accuracy Check

-8-
ACCURACY CHECK
!
IMPORTANT
Read this before using
the instrument.
This quality David White instrument
has been inspected twice for accuracy
before leaving the factory. The
instrument has also been given the best
protection possible against damage
during transportation. Even with these
precautions, the instrument is subject
to rough handling during shipment. To
protect yourself against the possibility
of using an instrument which is out of
adjustment, we suggest that you have
the instrument checked by a competent
person before using it.
The following test can be performed to
check the instrument’s accuracy.
Set up the instrument in an area that is
a level as possible and is about 200-ft
(60m) in length. Place two matching level
rods (or drive two pieces of strapping into
the ground) about 200-ft (60m) apart with
the faces toward each other. Position and
level the instrument so that the distance
from the instrument to each rod is the
same measure.
A
B
200’ (60m)
A
A
1
B
1
B
200’ (60m)
20’
(6m)
Take a reading on each rod with the
instrument where the crosshair is sighted.
Note the difference and record them.
Next, move the instrument to another
point in line with the two level rods.
A
B
200’ (60m)
A
A
1
B
1
B
200’ (60m)
20’
(6m)
Level the instrument and take readings on
the two level rods. The difference should
be the same (A - A
1
should equal B -
B
1
). The difference between A - A
1
and
B - B
1
is the instrument error at 200-ft
(60m).
Correction of instrument error should
be performed by an Authorized Service
Technician. The instrument should
be rechecked periodically to assure
continued accuracy.