5 Main Sources of Error in Levelling | Surveying

The following are the main sources of error in levelling: 1. Instrumental Errors 2. Errors of Manipulation 3. Errors due to Settlement of Level and Staff 4. Errors due to Natural Causes 5. Common Mistake in Levelling. Source # 1. Instrumental Errors: (i) Imperfect adjustment: The essential requirement in levelling is that the line of collimation must be horizontal when [...]