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Measurement of high accuracy requests precise focusing as well as continuous
measures.
(2) Obstacles
Measurement can be implemented if the staff is blocked less than 30%. Even if the
crosshair center is blocked, as long as the field of view is blocked less than 30%,
measurement still can be implemented. However, in this case, the accuracy might be
affected.
(3) Shadow
The surveying accuracy may be influenced if the staff is covered by shadow. In some
cases, it is not possible to measure.
(4) Backlight
If the background of the staff is very bright, it will affect the contrast of the staff, the
digital level might not be able to measure. You can cover something ahead of the
objective len in order to reduce the background light invading to the len. When a
strong light comes into the eyepiece, it might not be able to measure either. You can
also cover the eyepiece in order to block the strong light from coming into the
eyepiece.
When the sun is in a low position (for example, in the morning or at night fall), or if the
sun light comes into the objective lens directly, it is suggested to block the sunlight
with hands.
2.10 Surveying Note
In order to make full use of the functions of instrument, please pay attention to the
following:
(1) Set up the staff in bright place. If possible, prolong the staff completely. If
illumination is employed, it is suggested to illuminate the whole staff, otherwise the
accuracy might be affected.
(2) The shortest distance between instrument and staff is 1.5m.
(3) It will affect the accuracy when staff blocked. If the bar code on the staff is
