A 41 / 2 digit DMM has the error specification as: 0.2%

A 4¹ / ₂ digit DMM has the error specification as: 0.2% of reading +10 counts. If a dc voltage of 100 V is read on its 200 V full scale, the maximum error that can be expected in the reading is

Number of full digits = 4

Maximum count with 4	1	digits display
	2

= 19999
full-scale reading = 200 V

1 Count =	200 V
	19999

Then, error corresponding to 10 counts

= 10 ×	200	= 0.1 V
	19999

and, error corresponding to 0.2% of reading

= 0.2 ×	100	= 0.2 V
	100

Hence total error, E = E₁ + E₂ = 0.3 V

% percentage error =	E	× 100 % = ± 0.3%
	100