1. The accuracy limitations of the measuring device: For example, a digital scale may be accurate to 0.1 g, 0.01 g, 0.001 g, etc., a precision analytical balance may be accurate to 0.0002 g or 0.2 mg. 2. Instrument errors due to faulty calibration of an instrument. 3. Reading errors: Incorrectly interpreting interpolated values; inaccurate readings due to a fluctuating