GIAA Mailbag: On Tripod Adjustments and EDM Retroflectors

Questions and answers about the surveying and mapping industry.

Q: I know quality, well-adjusted tripods are more conducive to accurate surveys than poorer quality, unadjusted ones. What should I look for quality-wise and what adjustments are critical?

A: Whether to support targets, antennas or optical instruments, tripods form an important component of the system you rely upon to make required measurements. Quality tripods may be made from a variety of materials including, wood, metal, mostly aluminum and composites such as fiberglass. You should understand how much trading off weight and cost may affect the stability of your setup. This can only be evaluated by knowing the tendency of the tripod’s legs to lengthen or shorten with changes in temperature. This may occur from differential changes when the tripod is exposed to sunlight, which tends to cause rotation of the tripod head. Other changes that affect the stiffness and effectiveness of the joints and clamps may also mis-adjust the tripod. This information may be available from your dealer or the manufacturer. Maintenance checks should include: making sure the legs of telescoping tripods slide smoothly, that the head joints are stiff, that the clamps tighten and loosen effortlessly and smoothly, and that the points and shoes are not loosely attached.