132HC Mast SectionBrief introduction of tower crane measurement method in three common cases
In the installation of tower crane, we should pay great attention to the matters concerning the inclination. In construction survey, the verticality of buildings, structures, construction elevators, tower cranes, etc. is often measured. This paper introduces three common methods of tower crane measurement.
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I. for the measurement of Perpendicularity Error, 90 ° angle ruler is generally used to estimate the light gap based on experience, or 90 ° angle ruler is used to measure with feeler gauge. The above two methods can only be used for rough measurement of perpendicularity, and can not accurately read out the value of Perpendicularity Error, so the measurement error is large. The method of using dial indicator and 90 ° angle ruler to measure on the flat plate has achieved good results. The datum plane of 90 ° angle ruler is fixed on the tested piece with C-shaped chuck, and measured on the measuring plane of 90 ° angle ruler with dial indicator. The difference between the maximum reading and the minimum reading is the Perpendicularity Error of the measured part.
2. Conventional methods. If you want to measure the perpendicularity of a building, first set up a theodolite at a place 1.5 times the height of the building, aim at the top of the building, use the theodolite to make a mark, measure the horizontal distance between the theodolite and the bottom, and use the forward and backward mirror projection method to observe two measurements, and take the average value.
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III. If there is an obstacle near the building and people can't get close to the bottom of the building, they can first aim at the top of the building, throw it at a relatively flat place near the building, draw a short line, then aim the instrument at the bottom of the building, throw it at the same place, and draw a short line.
Using the above measuring method of tower crane has the advantages of small error, high accuracy, direct measurement of perpendicularity error value, convenience and high speed.
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