Appendix 3 - Determination of Power Set Point Stability
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Statutory Documents - IMO Publications and Documents - Resolutions - Marine Environment Protection Committee - Resolution MEPC.103(49) - Guidelines for On-Board NOx Verification Procedure - Direct Measurement and Monitoring Method - (adopted on 18 July 2003) - Annex - Guidelines for On-Board NOx Verification Procedure - Direct Measurement and Monitoring Method - Appendix 3 - Determination of Power Set Point Stability

Appendix 3 - Determination of Power Set Point Stability

  1 To determine set point stability, the power coefficient of variance should be calculated over a 10-minute interval, and the sampling rate should be at least 1-Hz. The result should be less than or equal to five percent (5%).

  2 The formulae for calculating the coefficient of variance are as follows:

(1)
(2)
(3)
Where,
%C.O.V. = power coefficient of variance in %
S.D. = standard deviation
Ave = Average
N = total number of data points sampled
Xi,Xj = ith, jth value of power data point in kW
i = index variable in standard deviation formula
j = index variable in average formula

  3 As an example, over the 10-minute sampling period, power is sampled at 1-Hz. This results in 600 data points being collected with values of x1, x2, x3...x600 and N is thus 600. The calculations would then be:

Parent topic: Annex - Guidelines for On-Board NOx Verification Procedure - Direct Measurement and Monitoring Method
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