TM 5-6675-330-12&P
Operating Notes
The following information facilitates rapid and pro-
per use of the instrument. Since the distance
measurement process is completely automatic, these
operating notes are intended to provide clarification
Of the instrument set-up procedures. The information
included here is particularly important when either
a new instrument is to be used for the first time, or
when an operator desires an initial familiarization
with the instrument.
1. Mounting.
The instrument is designed for mounting on a
tripod-mounted theodolite tribrach. If the tribrach
type is changed, a different mounting adapter
may be required.
2. Retro-reflectors (Prisms)
Since an offset correction can be dialed manually
into the instrument, the instrument can be used with
any prism whose reflection constant is known. The
supplied prism assemblies and adapters are
designed for mounting on a tripod-mounted
theodolite tribrach.
3. Instrument and System Offset.
The true distance between the vertical axis of an
EDM instrument and the vertical axis of a retro-
reflector usually differs from the uncorrected
distance computed by the EDM instrument. This dif-
16
ference is due to a combination of the retro-
reflector prism offset and the instrument offset. Prior
to shipment of each AutoRanger o Ilx EDM instru-
ment an offset correction, calibrated for that instru-
ment and a standard 30mm retro-reflector prism, is
entered into the instrument using the offset swit-
ches. The total offset correction (TOC) is stamped
on a decal affixed to the bottom-front of the instru-
ment. As long as retro-reflector prisms of the same
offset are used with the instrument, and the offset
switch settings are not disturbed, the display range
of the AutoRanger 0 Ilx EDM instrument will corres-
pond to the true range, with no need for operator
entry of offset corrections.
4. Bright Sun Caution.
Optical systems for EDM equipment are designed
for infinity focus. The sensitive detector is located at
the focal point of the receiver optics. Do not aim
the instrument directly at a bright sun.
5. Ready Light.
High accuracy is maintained in the
AutoRanger ® 11x EDM Instrument through use of a
window circuit that automatically monitors the
ranging signal. This circuit permits range com-
putations only when the return signal is within
preset limits. When the target has been properly
acquired and the CAL/START switch is pressed, an
internal servo system, automatically adjusts an op-
tical attenuator as required to bring the signal
level within the proper operating limits. Proper ad-
justment of return signal level is indicated by
Iighting of the READY Iight.
