Possible error while using planimeter for finding area of an irregular figure:
1) Instrumental Error
i) Roller of planimeter which must rotate the axis freely and withot vibrations,
if not, then causes error.
ii) The plane of the registering roller rim must be perpendicular to the axis of
the tracing arm.
2) Manual Error
i) Improper noting of zero, crossing the index point i.e. wrong number of ‘N’.
ii) Incorrect tracing of the boundary
iii) Error in noting initial reading or final reading.
iv) Failing to consider the area of the zero circle, in case the anchor point is kept
inside the area to be measured. (i.e. value of ‘C’.)
v) Error in calculation.
vi) Error in setting of arm length.
vii) Overlapping or repetition in tracing boundary.