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VERIFICATION OF MANUFACTURER’S CLAIM

If CVWR and/or CVT achieved are GREATER than those reported by the manufacturer, a
statistical test needs to be performed to determine whether this difference is statistically
significant by using the following equation :

• √

=
√
Where;
• is the manufacturer’s claimed imprecision

• = 1-α/q percentage point of the Chi-square distribution
• α = false rejection rate
• q = number of levels tested
• v = degrees of freedom and this instance is equal to D•(n-1)

a) Evaluation for Verification Manufacturer Claim (Within Run)

1. Calculate manufacturer’s within run SD (SDMWR) by this formula:
SDMWR = Manufacturer’s CV Within Run x Overall Mean (OM)

2. Calculate V = Degree of freedom = D*(n-1)
where(D: no of days, n: no of replicates)

then calculate √V

3. Determine C
2
C = Ӽ (0.05/L, V)
L: no of QC levels
If V=10 then C=20.48
• Obtain the value from Chi square table according to number of levelsand
degree of freedom

Then calculate √C

4. Calculate Verification Value within run SD (SDWRV)= SDMWR x √C
√V
5. Compare the estimated within run imprecision (SDWR) with Verification Value
Within Run SD (SDWRV)

• If SD WR≤SDWRV, imprecision of the test meets manufacturer’s claim.
(ACCEPTABLE)