| The right tribrach For accurate positioning over the surveying point. The stability of the tripod and tribrach is the primary influence on the accuracy of measurements and therefore it is important to use reliable and stable equipment. Perfectly suited to your instrument Leica Geosystems tribrachs are designed to operate reliably even in extreme temperatures, humidity and dusty conditions. In all situations, the maintenance-free foot screws ensure a movement that is always smooth and free of play. The support area of the tribrach is matched precisely to the base circumference of Leica Geosystems equipment. This provides extremely accurate forced centring. The optical plummet is of a robust construction, which virtually eliminates the need for adjustment during the lifetime of the tribrach. For tribrachs without optical plummet the innovative SNLL121 laser plummet provides for a convenient and rapid setup. Torsional Stiffness The top plate of the tribrach moves relative to the base plate when the mounted instrument is rotated. This force is most pronounced in motorized instruments, due to high acceleration and deceleration. The accuracy with which the tribrach returns to its original position, once the instrument has stopped rotating, is known as hysteresis. Since the hysteresis of the tribrach has a direct influence on the angular accuracy of the instrument, choosing the correct tribrach is important. |