Retro EDM Big Single Prism Reflector In Total Station 1Kg Metal

Sokkia AK17 Survey Accessory Reflection Big Single Prism for Surveying Total Station

Model: AK17

Specifications:

A.Prism Constant: 0mm/-30mm

B.Type: Single Prism

C.Effective Diameter: 64mm

D.Weight: 1Kg

E.For: Total Station (Sokkia, Nikon, Trimble, Pentax, Topcon etc.)

F.Package: Soft Carrying Bag

G.Target Plate: Metal

H.Category: Optics Instruments Accessory

Features:

The single prism with target assembly allows the user to quickly adjust the tilting target from behind the prism as it is pointing at the instrument to allow accurate sighting.

The prism can be either mounted in a 0 or -30mm offset position.

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. Certificates of compliance are available upon request.

 
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.