To lay down the procedure for rounding off the test results.
1.0 PURPOSE:
1.1 To lay down the procedure for rounding off the test results.
2.0 SCOPE:
2.1 This SOP is applicable for rounding off the test results in Quality control department.
3.0 RESPONSIBILITY:
3.1 Assistant – Quality Control
4.0 ACCOUNTABILITY:
4.1 Executive – Quality Control
5.0 PROCEDURE:
5.1 Analytical results observed in the laboratory (or calculated from experimental measurements) are compared with stated limits to determine whether there is conformance with compendial assay or test requirements.
5.2 The observed or calculated values usually will contain more significant figures than there are in the stated limit, and an observed or calculated result is to be rounded off to be number of places that is in agreement with the limit expression by the following procedure.
Note: Limits, which are fixed numbers, are not rounded off.
5.3 When rounding off is required, consider only one digit in the decimal place to the right of the last place in the limit expression.
5.4 If this digit is smaller than 5, it is eliminated and the preceding digit is unchanged. If this digit is greater than 5, it is eliminated and the preceding digit is increased by one.
5.5 If this digit equals 5, the 5 is eliminated and the and the preceding digit is increased by one.
Illustration of rounding numerical values for comparison with requirements |
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Compendial Requirements |
Unrounded Value |
Rounded Result |
Conforms |
|
Assay limit ³ 98.0% |
97.96% |
98.0% |
YES |
|
97.94% |
97.9% |
NO |
|
|
97.95% |
98.0% |
YES |
|
|
Assay limit £ 101.5% |
101.55% |
101.6% |
NO |
|
101.46% |
101.5% |
YES |
|
|
101.45% |
101.5% |
YES |
|
|
Limit test £ 0.02% |
0.025% |
0.03% |
NO |
|
0.015% |
0.02% |
YES |
|
|
0.027% |
0.03% |
NO |
|
|
Limit test £ 3 ppm |
0.00035% |
0.0004% |
NO |
|
0.00025% |
0.0003% |
YES |
|
|
0.00028% |
0.0003% |
YES |
|
1.1Report the results as per the specification.
Rounding off the test results, quality control, limit expression
