Counting with a scale
When counting, the scale's evaluation device calculates a number of pieces instead of a weight from equal parts. To calculate, the weight value on the weighing platform is compared with the reference weight.
The reference weight is the theoretical weight of a part. It indicates the average weight of a piece. The reference weight is calculated by weighing parts and the number of parts. The number of parts is called the reference number of pieces.
The reference quantity contains the number of parts used to determine the reference weight. 10 parts are usual, but if the reference weight varies greatly, more parts should be used.
When determining the reference weight, the error increases considerably if
- the reference quantity is small,
- a part is less than 1 e.
Example:
The nominal weight of a part is 2.5 g. Due to tolerances, the actual weight varies by 1% between 2.475 g and 2.525 g.
The evaluation device counted 1000 parts. Due to the scatter, this could be 990 or 1010 parts.
Process using the example of the 83sigma evaluation device with activated counting function:
DETERMINE REFERENCE WEIGHT
The reference weight is used for counting. Before you can start counting, the reference weight must be determined or entered.
1. Select the weighing platform with the smallest division.
2. Check zero position.
3. Place container on weighing platform.
4. Press the tare button. (Only press the tare button if you are using a container.)
5. Place parts on the weighing platform. The main display shows the weight of the parts.
6. Enter the number of parts using the keyboard.
7. Press the function key to determine the reference weight. The reference weight has been determined. The main display shows the number of parts. The secondary display shows the total weight of the parts and the determined reference weight per part.
You have determined the reference weight.
To increase the accuracy of counting, the determined reference weight can be optimized on the 83sigma. The optimization is displayed as follows:
The trend arrows on the main display show whether you need to add more pieces or remove some. If both trend arrows are displayed at the same time, you need to increase the initial number of pieces and determine the reference weight again. If no arrow is displayed, further optimization is not possible.
ENTER REFERENCE WEIGHT MANUALLY:
A manually entered reference value cannot be optimized and counting
therefore less accurate.
Enter the reference weight:
1. Enter the reference weight in g using the keyboard.
2. Press the function key to enter the reference weight.
You have entered the reference weight.
counting process:
After you have determined or entered the reference value, you can start counting.
Count a number of parts:
1. Check the zero setting. By zeroing you remove the tare from a container.
2. Place the initial quantity on the weighing platform.
3. Determine or enter the reference weight.
4. Optimize reference weight.
You can only optimize determined reference weights.
5. Place all parts on the weighing platform.
The main display shows the number of parts counted. The secondary display shows the net weight of the parts counted and the reference weight per part.
You have counted a number of parts.
In the following video, the reference weight is first determined using the reference scale. Then it is counted on the quantity scale.
ANOTHER EXAMPLE:
In the example, the Count function is used to count a container filled with screws. The number of pieces can be calculated because the average weight of a screw and the total weight of all screws are known. What is unknown is how many screws are contained and how much a screw weighs.
Example Count the contents of the filled container:
1. Select weighing platform.
2. Check zero position.
3. Place the filled container on the weighing platform.
4. Enter the weight of the empty container.
5. Press the manual tare button. The empty container is tared.
6. Press the tare button. The screws are tared.
7. Remove number of screws.
A few screws are enough. It is important that you know the number.
8. Enter the number of screws using the keyboard.
9. Press the reference quantity key.
The number of screws removed is displayed.
10.Put removed screws back into the container.
0 removed screws are displayed.
11.Press the C/AC key and then the tare key.
The taring of the screws is cancelled. The number of screws is
displayed.
You counted the contents of the filled container.
A handheld scanner and/or a USB stick can also be connected to the 83sigma or 84vario evaluation device. It is possible, for example, to query the article number. This can then be typed in or scanned. The data (sequence number, date, time, article number, number of pieces, piece weight, bulk weight) is then sent to the USB stick and saved. The data records generated can then be imported into the PC using Excel and further processed.
By the way, you can also combine the counting function with the target weighing function . This makes sense if, for example, you want to fill a certain number of parts. The unit weight is then first determined on the reference scale, the target value (e.g. 1000 pieces) is entered and then filled on the bulk scale. The evaluation device shows how many parts have already been filled. If the target value has not yet been reached, a yellow LED lights up; if it is exceeded, a red LED lights up; and green when there are exactly 1000 parts in the container.
For small reference weights in large quantities, a counting system makes sense. Here, the reference weight is determined on a small scale and the large quantity on a second, larger weighing bridge.
The evaluation devices 83sigma, 84vario and 82e-2, 82c-2 and 82c-1 have the counting function integrated, although the operation is of varying levels of convenience.
Of course, we also have other counting scales...
