Specifications

11
USING THE MINIMUM SAMPLE SIZE AND MINIMUM ACCURACY FEATURE
Counting errors can be caused by non-uniformity in the parts being counted
or by insufficient sample weight. To reduce these errors your scale has been
designed with two special features. The minimum sample size feature en-
sures that the scale will calculate an average piece weight which is nearly
equal to the average piece weight of the entire lot. This feature prevents an
operator from using a sample size which is too small that could be “biased”,
i.e., not truly representative of the distribution of unequal parts in the lot to
be counted. Setting the scale to require a larger minimum sample will
reduce the error which is introduced by non-uniformity.
The minimum accuracy feature ensures that the total sample weight is
heavy enough to keep counting errors very small. The higher the degree of
accuracy desired, the larger the total sample weight that will be required.
This means that even if the sample satisfies the minimum sample size re-
quirement it may still be too light to achieve the accuracy level selected and
therefore the scale will request more pieces.
Your scale has been preprogrammed at the factory with a minimum sample
requirement of 10 pieces and a minimum accuracy requirement of 95%. If
you wish to change these settings contact your local authorized Setra dealer
or refer to the Setra Easy Count Technician’s Guide.
COUNTING WITH ACCURACY ENHANCEMENT
When counting parts that are not uniform in weight, you can periodically
update the average piece weight (APW) and thereby increase the accuracy.
Each time the count key is pressed, the scale will update the APW as long as
the additional weight is less than or equal to the previous sample weight. If
the added weight is more than 100% of the previous sample, the APW will
not be updated. For example, if you start with a sample size of 10 pieces
then add 10 more and press the count key, the APW will be recalculated
based on a 20 piece sample. The next time you want to update the APW you
can add up to 20 pieces. If you add 11 or more to the original 10 piece
sample, the APW will not be updated and will continue to represent the
original 10 pieces. To count using this accuracy enhancement feature, fol-
low the procedure below.
1. Place an empty container on the scale and press the zero key.
2. Press the sample size (EZ6) or count (EZ2) key. The scale display will
say “Add 10” PC.