According to RTU Syllabus
SURVEYING
LINEAR AND ANGULAR MEASUREMENTS
Part-4
Mistakes & Errors
Mistakes-
They are caused by carelessness or poor judgement.
ex-
- A reading of 10m is booked as 1m.
- Miscounting the no.of tape lengths. etc.
These can be revealed by taking the same measurement again with the same instrument.
Errors
- It does not arise due to mistake.
Errors are classified as-
- Systematic error/Cumulative error
- Random error/Accidental error/compensating error
Error = Measured value - True value
Correction = True value - Measured value
Systematic Error/Cumulative Error
- These Errors follow a definite mathematical or physical law.
- They are cumulative in nature.
e.g.-
Expansion of steel tape due to increase in temperature.
- These Errors can be checked by remeasuring the quantity by a different method using different instrument.
Random Error/Compensating Error/Accidental Error
- These are the Errors which remains after the mistakes and systematic errors are removed.
- They are random in nature.
- They are mainly caused by limitations of observer and instruments.
Aditi Sharma
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