Specifications

Scale Operations 39
4. Press SHIFT DOWN + NET/G. The weight display should now show 0.500 and the net weight annunciator is
illuminated again.
5.5 Entering Unit Weights
Entering unit weights can be done either by sampling, as presented in Section 5.5.1, or by key entry as described
in Section 5.5.2.
Note: SPEC 03 EXTENT OF INSUFFICIENT SAMPLES controls unit weight sampling. The default setting for the SPEC is 0.1
percent.
Note: SPEC 63 SAMPLE QUANTITY determines the number of pieces the scale assumes are on the platter when you press the
PIECES key to calculate the unit weight. The default setting for the SPEC is 0: 10 pieces.
Note: SPEC 64 SCALE A <–> B sets whether the unit weight determined by sampling is automatically transferred from Scale A
to Scale B. The default setting for the SPEC is 0: MANUAL.
When you have a procedure that involves sampling an item’s unit weight on the DC-200/300’s built-in platform
and then want to go immediately to weighing and counting boxes or bins on a floor scale or other external scale,
set SPEC 64 to 1: AUTO. If the external Scale B is not necessarily going to be used for weighing the same item
as is being sampled on Scale A, set SPEC 64 to 0: MANUAL.
Note: SPEC 65 UNIT OF PCS WT controls whether the unit weight is displayed per 1000 pieces or per 1 piece. The default
settings for this SPEC is 0: 1000 pieces.
Unit Weight per 1000 Pieces vs. Unit Weight per 1 Piece
The scale’s internal microprocessor calculates unit weights to 7 or 8 decimal places. However, the scale display
generally can only show Unit Weight to 5 characters. If this Unit Weight is recorded from the scale display and
entered by key entry, this can introduce errors in the Unit Weight and consequently in the counts. This error
increases as the Unit Weight of the parts being counted decreases.
Example: A sample of 10 zener diodes is placed on the scale. The Unit Weight is computed to be 0.0006536 lbs.
However, the scale has a 5 character display for Unit Weight so the scale can only display.0065 as the Unit
Weight. If this Unit Weight were recorded and keyboard entered in future counting operations, the resulting error
would be: 00065 =.55%
.0006536
On the other hand, with entry of the Unit Weight as “weight per 1000 pieces” the decimal place is, in effect,
moved three places to the right, allowing 3 more decimal places of accuracy. In this example, the entry would be
made as 0.6536 per 1000 pieces, eliminating the error.
As a practical note, entering unit weights per 1000 pieces also lessens the chances of entering the wrong number
of zeros when keying in weights with many leading zeros. Misentry of unit weights is a common cause of
inaccurate counting.
Note also that when SPEC 65 Unit of Pcs Weight is set to 1: Unit Weight per 1 piece (this is also called “average
piece weight” or APW), the scale will not accept a sample that produces an APW of less than 0.01 lbs, regardless
of the scale capacity. If the APW is less than 0.01 lbs, the error message
DATA INVALID will appear to warn the
operator that the part is too small to be counted using APW and that the unit weight/1000 pieces should be used
to count this piece. Remember that if average piece weight (unit weights per 1 piece) have been stored in
memory with an Item Code, these unit weights will not automatically be converted to unit weight per 1000 pieces
when the item is recalled from memory. If you are changing SPEC 65 to operate using unit weight per 1000
pieces, you should update the unit weights associated with item codes in memory or eliminate the unit weights in
memory and establish them by sampling or key entry at the time you recall the Item Code. (See Section 6.1.2 for
more information on how to program items into memory).
When might you want to use unit weight per 1 piece? Generally in one of two cases:
1. If you are working with other existing systems or procedures that are already set up to record unit weight
per piece (inventory systems, labeling requirements, etc).
2. If the unit weight or your pieces is more than 100 lbs, as in the case of some castings, engine parts and
the like. When the unit weight is over 100 lbs, the number of digits in the scale’s Quantity display will
not be able to fully display counts of more than 100 pieces.