Triplet Offset Targets, .25" Dot Size
Triplet Offset Targets ("Triplets") are a joint development from DCS and Photometrix. Triplets are used specifically with iWitnessPRO.
Triplet Offset Targets are made from red retroreflective material and are production die cut to provide high 3D measurement accuracy when combined with iWitnessPRO. Triplets can be purchased as plastic-mounted, hard-backed or as removable, adhesive-backed. The hard back is formed from .03" thick black plastic, and the target can be re-used as many times as required. The adhesive style Triplet target can also be re-used.
How they work:
The tip of the triplet is positioned at the feature point of interest and iWitnessPRO calculates the 3D coordinates of the tip from the measured positions of the three retroreflective dots. Within iWitnessPRO, a blue point label is shown for the tip in the image view, and a red label appears in the 3D view. Click here to see an illustrated example project, which used a sink template and hard-backed triplets. By clicking one button in iWitnessPRO, all triplets are automatically measured. Click here to see a measured .25" Dot triplet in the iWitnessPRO 3D view.
Where to use them:
Triplets are ideal for rapidly marking and automatically measuring object points which are difficult to physically target, edges and corners for example. This is especially beneficial when complex geometries are involved, as is often the case in reverse-engineering where high-accuracy measurement is required.
The accuracy of the final 3D tip position is at the same level as the photogrammetric measurement accuracy of the retroreflective targets forming the triplet. The sink template project used a consumer grade DSLR camera, with iWitnessPRO produced 3D coordinates of the triplets to an accuracy of 0.004" (0.1mm).
There are two standard triplet sizes. For triplets with 0.25” dots, the camera-to-target range can extend to about 25' or 8m when using a consumer grade DSLR cameras with a lens of 18-24mm focal length. For Triplets with 0.15” diameter dots, the maximum camera-to-object distance for the same range of focal lengths is generally about 10’ or 3m.
Tip Sheet for Surveys using Triplets:
Click here to review a reference guide to the use of both .25" and .15" triplets with iWitnessPRO Version 2. Further details are available in the iWitnessPRO User Manual.
Click here to see the hard-backer .25" dot style Triplets.
Click here to see the adhesive-backer .25" style sheet of Triplets.
Click here to see an example project of measuring a Shower Enclosure.
Triplets can also be combined with PTs, FPTs and STTs in the same project as well as with natural feature marking.
Both Hard-backer and Adhesive-backer designed Triplet targets are available for $99.00, the set being Qty. 100. Please call for ordering the adhesive backed Triplets; hard-backer style Triplets are available as an online purchase.
Shipments are typically made within 48 hours of receipt of the order.
To order, use the Online method
Triplet Offset Targets are shipped via USPS.
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