Spectra Precision FAST Survey Reference Manual - Manual (Page 363)

p361
 Read Method
: The available read methods are Fast, Tracking, User-Defined, and Reflectorless. The default
setting is Fast. The "Standard" option produces a 3-second reading while the “Fast” setting produces a 1-second
reading. One application of Reflectorless is to toggle between a 0 prism offset (shooting a rock face or brick wall)
versus shooting a prism with a non-zero prism offset. When set to Reflectorless, the rod height and prism offset
automatically change to zero. When returned to Standard, the previous non-zero prism offset is recalled, and the
original rod height is restored. Turn to Point for stakeout and PowerSearch are disabled in Reflectorless mode.
The Read Method (Std, Fast, Reflectorless) will appear in the upper right of the graphic screen for most types of
Leica total stations, in commands such as Store Points, Stakeout Point, etc.
 Foresight/Backsight Prism Offset
: Here is the list of standard prism offsets. Note that Leica prisms default zero
to equate to -34.4 mm. So a prism offset of 34.4 equals a zero “net” offset. Whenever a prism constant is changed,
a note is written to the raw (RW5) file. When you select one of the prisms from the list (Circle, Mini, etc), the value
that is shown in parenthesis is the actual value sent to the instrument. i.e. 0.0 for Circular, 17.5 for Mini. If you
select "30mm" or "40mm", - 4.4 and 5.6 are sent, respectively (30-34.4 and 40- 34.4). You may also type in any
value you choose. In this case, we will send that value exactly, unmodified, to the instrument.

23.1 (360): Leica Model

4.4 Mini (360)

34.4 (0mm)

0.0 (circle): Standard Leica round prism.

17.5 (mini): Leica mini prism.

34.4 (ReflTape): Equates to zero offset (wall, surface).

4.4 (30mm): Other manufactures (Sokkia, Seco).

-5.6 (40mm): Other manufacturers.
 Laser Pointer
: Ideal for indoor or dark evening surveying, this feature causes the instrument to emit a red beam. It
is often used when doing reflectorless work and makes a red mark on the wall, floor or object being surveyed. This
is usefule for confirming the position prior to the shot. The beam should not be directed into someone’s vision or
eye.
