Product Description

803-CP Invar Kit for Photogrammetry

English unit kit with retroreflective targets

The 803-CP is designed as a calibration reference or scaling kit for three-dimensional measuring systems using photogrammetric or related technologies. They can also be used in the construction of monuments or artifacts for “leapfrogging”, providing stable transfer points and retroreflective targets. Included are four retroreflective targets which have been 100% inspected at the factory using photogrammetric measurement techniques. The target mounts are unique to this kit and fit only the supplied target holders.

Invar tubing is great for metrology because it has such a very low coefficient of thermal expansion, which effectively eliminates changes in length due to handling or environmental changes. 

The Invar tubing in the 803-CP is manufactured to its stated length within ±0.0001″. In addition, the Invar tubing components are hand-picked for each kit so that the total stackup error does not exceed 0.0005″. This means that you can connect all of the tubes found in a given kit together end-to-end, and the stack will maintain the total length within the stackup error. (The table above right summarizes this information.) We often recommend the 803-CP when people ask for a calibration or scaling-quality type system.

Individual components may be assembled to produce lengths from 2″ to 112″, in 5″ increments. The table below specifies all included components.

803-CP Invar Kit Components

803-CP Components

Picture Part number Description Qty
A 12587-20IN 20″ Invar tube 4
12587-10IN 10″ Invar tube 2
12587-5IN 5″ Invar tube 2
B 15483-1 Retroreflective target; 1/4″ dot, 1″ offset 4
C 15484-1 Target holder; 1″ offset 4
D 12406-G1 Stainless steel connectors 10
n.a. 12421-G1 Plastic case 1
n.a. n.a. NIST traceable certification for kit yes


Approx. weight:
Kit and case, 17 lbs.
Shipping, 22 lbs.
Thermal expansion coefficient:
0.70×10−6 in./in./°F for temperature range of 0°F to 200°F
Invar tubing:
1″ diameter Invar with stainless steel end caps, having 3/8″-24 internal threads on each end
Finish: Oil and stain resistant PVC jacket, red
Case: Plastic case with foam insert


English (PDF)