CALCULATION OF RESULTS AND ERRORS

1. errors

2. uncertainties

Measurements invariably involve in (2)

acceptable accuracy

We can only hope to minimize errors and estimate their size with

1. faulty calibrations

2. standardizations

3. random variations

4. uncertainties

Errors are caused by (4)

1. Frequent calibrations

2. standardizations

3. analyses of known samples

These (3) can sometimes be used to lessen all but the random errors and uncertainties.

measured value and the "true" or "known" value.

Error refers to the difference between a ______ and the ________

estimated uncertainty

Error often denotes the ______ _______

in a measurement or experiment.

formula for error and percentage error

Duplicate results

check very closely are not an assurance of accuracy, as is often taken for granted by the beginner in quantitative work, since errors inherent in the method and apparatus used may be repeated for each sample

discrepancies in the results

They are caused by various sources of error to which all experimental data are subject.

1. individual analyst

2. faulty procedure

3. apparatus errors

causes of errors

apparatus errors

Errors of this type are usually detectable and so may be eliminated to a large extent.

apparatus errors

due to poor construction or calibration