difference between null and deflecting instrument.

Answer Posted / sandy

The accuracy of these two instruments depends on different
things. For the Null type ins it depends on the linearity
and calibration of the spring, while for the second it
relies on the calibration of the weights. As calibration of
weights is much easier than careful choice and calibration
of a linear-characteristic spring, this means that the
second type of instrument will normally be the more
accurate. This is in accordance with the general rule that
null-type instruments are more accurate than deflection
types.

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