Keywords: Levelling, precautions, errors in leveling
Since you have acquired a good understanding about leveling, let’s now move on to the last topic in this section.
Levelling has to be done with utmost care to obtain accurate and precise readings. Any error in the readings could possibly harm all the calculation and subsequent surveying processes.
Following are the main points that a surveyor has clear understanding before proceeding to levelling on the field.
- The staff should be kept vertically for accurate reading. There is also an alternative method, i.e., to wave the staff and take the lowest reading. Both methods are equally effective.
- The bubble in the dumpy level should be central to obtain an accurate line of sight.
- The foot screws in the dumpy level should be used carefully
- To avoid errors, read the staff in the increasing direction of readings
- Take the reading on the portion of the staff between two vertical crosshairs.
- Equalize foresight distance and backsight distance
- Tripod should be carefully placed in the required point and should not be disturbed at any cost.
- Use a firm and fixed point for turning point/changing point
- Eliminate all the minor and major errors especially parallax before readings are taken
- Avoid mistakes in reading (make sure that the metre and decimeter are correctly noted).
- Avoid work in very hot climate because it may harm the instrument. So the instrument should be protected from heat.
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