Background Image
Table of Contents Table of Contents
Previous Page  430-431 / 620 Next Page
Information
Show Menu
Previous Page 430-431 / 620 Next Page
Page Background

Table 2

Nominal

T

stat

p

-value

1.87

0.1

1.87

0.1

1.96

0.0

1.99

0.0

2.00

0.0

1.92

0.1

1.93

0.0

1.93

0.0

1.86

0.1

Mean

1.93

0.1

SD

0.1

0.1

T

stat

=

where: = mean of the differences between measured results and reference value

sd = standard deviation of the differences between results and reference value

n

= number of replicate analyses of SRM

H

0

: = 0, The null hypothesis is that there is no difference between the measured results and the certified value:

p

-value: is the probability (at the 95% levels of confidence) of obtaining the test statistic assuming that the null hypothesis is true.

p

-value < 0.05 indicate a difference of statistical signifance between measured results and SRM.

95% confidence interval: The true population of the measured value expected to fall within the confidence interval estimate 95% of the time.

lower limit = mean -

upper limit = mean +

where: = critical values of the t-distribution

sd = standard deviation of the differences between results an reference value

n

= number of replicate analyses of SRM

1.9 - 2.0

Bias

Confidence interval

-0.1

3.040

0.016

SRM 1849a

Cu (mg/100g)

1.978

0.026

1.952 - 2.004

Accuracy - Analytical bias compared to reference material

Certified Reference Material

Measured Results

CRM product

Analyte

Certified value Uncertainty Certified range Concentration

Difference from

certified value

n

/

sd

d

d

d

n

t

crit

sd

n

t

crit

sd

crit

t

SPIFAN ERP Checklist v1.0

MTE-02 MEF Form

FOR ERP USE ONLY

DO NOT DISTRIBUTE