Timble Type 360 Degree Surveying Prism for Robotic Total Station
Model: TB360
Specifications:
Prism Constant: 2mm
Prism Angle Accuracy: ≤5"
Prism Size: 25.4mm
Target Range:400m
Features:
Trimble Type 360 degree prism assembly features seven 25.4mm
silver-coated prisms and incorporates a protective rubber bumper on
the exterior ring.
The built in bulls-eye bubble helps keep the prism level when used
with a stakeout point.
The prism has a 5/8*11 mounting thread.
This 360 prism is compatible with all robotic total station like
Trimble, Topcon, Sokkia, Leica etc.
Optical Survey Prism Applications:
Survey prisms are used by surveyors and engineers to measure the
change in position of a target that is assumed to be moving. Survey
prisms are used for a wide range of monitoring applications
including:
- Rail Monitoring
- Settlement Monitoring
- Displacement Monitoring
- Deformation Monitoring
- Convergence Monitoring
Prism Range
Surveying Prisms, also known as retro-reflectors, redirect a
measuring beam back to the EDM (Electronic Distance Measurement)
for processing distance. There are two main factors for good range
measurement: prism diameter and beam deviation. If the beam
deviation is not accurate then the returned beam will miss the EDM
completely. This occurs mainly near the maximum range of the EDM.
Prism Holder Accuracy
Prism accuracy is determined by the physical location of the prism
in its canister and then to the prism holder.
Survey Prism Offsets
Some Surveying Prisms have an offset due to the fact that the
transmitted beam from the EDM takes longer to enter and exit the
prism. The longer time translates to a longer distance measured.
The distance is corrected by using an 'offset' and/or positioning
the prism in relationship to the plumb line of the prism holder.
Common offsets are 0, -17.5 mm, -30 mm, -34 mm, and -40 mm. The
offset is determined by multiplying the height of the prism against
the refractive index of the glass used.
