The NA2 universal automatic level meets all requirements regarding precision, convenience and reliability. It was designed by surveyors and development
engineers with years of experience and who know what a field instrument
has to be able to do. The NA2 soon pays for itself, because it can be used for all types of surveying job; on building sites for routine levelling, in engineering projects, and for geodetic control at all levels of accuracy.
Universal application:
Levelling of all types and all orders of accuracy
Precise levelling and settlement determinations on buildings
Routine heighting for the construction of roads, railways, pipelines, tunnels and so forth
Setting-out work and control measurements on the construction site
Area levelling of high Accuracy
Tacheometric levelling with the K-version on flat terrain by combining stadia and angular measurements with height readings
Deformation measurement and monitoring of bridges
Adjust the line of sight automatically
Easy to level up
The advantage of this instrument is that, as soon as the bubble is centred,
the line of sight is horizontal for all pointings of the telescope. The observer is
freed of the time-consuming centring procedure involved with the traditional tubular level, and can concentrate on the business of staff readings.
Robust and automatic
The compensator is essentially a pendulum with a prism (4). The suspension system comprises four flexed tapes (1) made of a special alloy to ensure faultless
functioning even at extreme temperatures. The compensator, which is located
between the focusing lens and the crosshair reticle, is pneumatically damped
against mechanical vibration and is screened against magnetic fields.
Minimum maintenance
In the unlikely event that the compensator is damaged (and this can only
happen as a result of extremely harsh treatment) it is replaced easily, being
held only by three screws.
Top-class optics
The telescope is of excellent quality and gives a bright, high-contrast, erect image,
even in poor light – an essential for accurate levelling. With the standard eyepiece the magnification is 32×, the optimum for most applications of the
instrument. Optional eyepieces are available; the 40× may be preferred for
precise levelling, the 25× in hot, shimmer conditions. Eyepiece exchange takes
only a second or so. The focusing knob has a coarse/fine movement:
– coarse, for rapid setting with minimum turning
– fine, for the final delicate touch to give the perfect image.
Fatigue-free viewing
The reticle has:
– a single horizontal hair for reading normal staffs
– a wedge-shaped hair for use with invar staffs
– stadia hairs for distance measurement and threewire levelling.
The general layout of the controls, the smooth friction-braked rotation
of the instrument, and the endless horizontal drive with bilateral knobs,
all combine to make the instrument easy to use.
At an advantage on unstable ground
If a tubular level is used on unstable ground it tilts out of range and has to be
continuously reset. By contrast, the pendulum of the NA2 “compensates”
and keeps the line of sight horizontal.
Angle measurement with the NAK2
Civil engineers and contractors often require a circle for angle measurement
and setting-out work. Even simple detail surveys, by taking angle, distance and
height, and plotting with the polar method, can be done with a level. The model NAK2 has an internal glass circle which is read via a scale microscope and which can be set to any value by turning the rim around the base of the instrument.
Strong tripods
In principle, the NA2 can be set up on any Leica Geosystems tripod. In
practice, for all-round purposes, we recommend the heavy-duty GST20
telescopic-leg tripod. For precise level ling the GST40 fixed-leg tripod
is suitable because of its extreme rigidity. The modular relationship
between instrument and tripod is an advantage when transport space is
limited.
Centring is easy
The circular level only needs to be centred approximately to bring the
compensator well into its working range of ~30', and so setting-up goes quicker.
The bubble is viewed positively via a pentaprism and is monitored down
the eyepiece.
Play-free foot screws
The pitch of the smooth running and backlash-free foot screws is such that
the bubble can be centred in a very short time. Independent of temperature
Unlike the tubular level of a traditional instrument, the NA2 universal automatic
level is relatively insensitive to direct solar radiation and an umbrella need only
be considered for the most precise levelling.
Independent of temperature
Unlike the tubular level of a traditional instrument, the NA2 universal automatic
level is relatively insensitive to direct solar radiation and an umbrella need only
be considered for the most precise levelling.