Table of Contents
Advertisement
R
11 STATISTICS TERMINOLOGY
Term
COEF OF VARIAT'N
HIGHEST READING
LOWEST READING
MEAN
NO. OF READINGS
STD DEVIATION
PERCENT GREATER
OR EQUAL TO NDFT
PERCENT BETWEEN
90% AND 100% NDFT
90:10 PASS / FAIL
38
Meaning
Coefficient of Variation. The standard deviation divided by the mean for a group
of readings, expressed as a percentage.
The value of the maximum thickness in a group of readings.
The value of the minimum thickness in a group of readings.
The average of a group of readings; the sum of the individual readings divided
by the number of readings.
Number of Readings. The running value for the number of readings taken in a
group. In the case of the mode, the Number of Readings is the number of
values recorded, not the total number of readings taken.
Standard Deviation. A statistical measure of the spread of values in a group of
readings.
The percentage (%) of readings greater than or equal to the value of NDFT (see
"Set NDFT" on page 31)
The percentage (%) of readings less than the value of NDFT but greater than
90% of the value of NDFT.
90/10 test results:
= pass,
below 0.9xNDFT (if a number between 1 and 10 is displayed, insufficient
measurements have been taken to be statistically valid - take more measurements)
= failed on 90% test,
= fail due to a reading
Advertisement
Table of Contents
