Scale Operations
19
5.0
Scale Operations
The following sections contain detailed operator instructions for the DC-782 counting scale (see Figure 5-1).
Included are instructions on how to enter tare weights, how to enter unit weights, and how to perform counting
operations.
Figure 5-1. DC-782 Counting Scale
5.1
Counting Scale Accuracy
Counting scale accuracy is primarily determined by the following factors:
•
Sample size (number of pieces)
•
Total sample size as a percentage of full scale capacity
•
Piece-to-piece weight variation
As a general rule when determining sample size of fairly uniform pieces, the larger the sample size the greater the
total sample weight, therefore, the better the counting accuracy. Selecting the smallest capacity scale that can
obtain the highest counting resolution should be considered, but should not sacrifice the capacity required for the
heaviest container of parts.
There is a direct relationship between piece-to-piece weight variation (non-uniformity) and counting accuracy
.
Therefore, elimination of the piece-to-piece weight variations can be accomplished by:
1. Isolating the sample used to calculate the unit weight and use the same sample to re-check the scale.
2. Recalculating the unit weight from lot-to-lot of parts. Parts manufactured on one machine may vary
slightly from another machine relative to weight.
3. Tightening the manufacturing tolerances on the parts reduces piece weight variations and increases count
accuracy.
Parts can vary greatly in their value. With parts of lesser value per piece, the extra sampling and time involved in
trying to achieve 100% accuracy as opposed to 99.5% may not be cost-effective. However, with high value
items, 100% accuracy is vital. The DC-782 Counting Scale has the precision to help you with both situations.
5.2
Setting Tare Weights in Weighing Mode
This section will describe the different tare-related operations you can perform from the weighing mode. Tare
weight can be set by one touch tare using the
TARE
key or, if the value is known ahead of time, can be entered
digitally using the digital tare function. Tare addition and subtraction can also be done digitally or by using the
TARE
key. Finally, an existing tare stored with an Item Code can be overridden temporarily in the Weighing
Mode if needed.
All manuals and user guides at all-guides.com
