simple about repeatability

1. DEFINATION OF REPEATABILITY
Repeatability or test-retest reliability is the variation in
measurements taken by a single person or instrument on the
same item and under the same conditions. A less-than-perfect
test-retest reliability causes test-retest variability. Such variability
can be caused by, for example, intra-individual variability and
intra-observer variability. A measurement may be said to be
repeatable when this variation is smaller than some agreed limit.

2. HOW REPEATABILITY MEASUREMENT
ERROR
1. various reasons can cause errors, which are a problem with
the equipment, the reading problem with the equipment, and
many more.
2. in cause to avoid the error, the reading at the same place
over and over again to be taken to get the average range.
3. to get the average range, the value should be in the same
place and with the same tools on the table last post.

3. HOW TO ELIMINATE REPEATABILITY
1. Calculate the mean or average of your data. To do this, add
your measurements and divide by the number of elements in
your sample. For example, if your measurements are 1, 2, 2,
3, 2, the average would be 2 -- 10 divided by 5.
2. Calculate the variance of your data. To do this, calculate the
difference of each result from the mean, square each result
and work out the average. For example, if the difference from
the mean in a set of data were 1, 2, -2 and -1, the variance
would be 2.5. That is, the average of 1, 4, 4 and 1.
3. Calculate the square root of the variance. This is the
repeatability standard deviation of your data. Following our
previous example, the standard deviation would be 1.5811.

4. IMPORTANT OF REAPITABILITY
1. It is important to get a reading repeatibility, this is to get the precises
value.
2. important to take readings 3 times or more to get the average range to
avoid the error because there is no tool that can provide accurate
readings over and over again.

5. CONCLUSION
Repeatability is important in every measurement work, it is to get the precises
value to avoid any problem, because, a tools cannot give a precises value in
every single calculation