Counting Scales

Decision support when purchasing counting scales:

The main task of the counting scales is the piece number determination with the help of the weight measurement.

So, it means that if there are 10 pieces on the scales and the total weight is 20 g, then the piece weight is 2 g. As a result, if the total weight is 200 g, there must be 100 pieces on the scales.

The determination of the number of pieces is based on the rule of three, whereby the counting scales always require the piece weight for the counting.

The transmission of the piece weight to the counting scales is the biggest difference between the individual counting scales and should be adapted to the task field.

In the simple models of counting scales, the counting function is a just one of many and not the main feature of these scales. The piece weight can only be determined by the scales with the help of the reference piece numbers. These counting scales look like regular scales and may not be recognized as counting scales at the first glance.

The process looks like this:

- The user places 10 pieces on the scales.
- In the counting function, the user is given the reference piece numbers of e.g. 5/10/20/50/100 etc., which the user has to confirm then. In this example, there are 10 parts.
- Since the scales know the total weight and the number of pieces, the piece weight can be determined by the balance itself.

This type of the counting scales requires, before each article change, the count of a reference piece number as well as the procedure described above.

It should be taken into consideration that not every part has exactly the same weight. Therefore, there may be total miscounts due to the weight tolerances of the individual parts.

In order to avoid these miscounts, the largest possible number of reference pieces should be used, especially for light parts, in order to obtain a representative average piece weight.

So, if several products are counted but they are frequently changed, the counting with these counting scales is impractical.

In this case, the counting scales with the piece counting function as their main task should be used. This type of scales differs significantly from regular scales.

This type of the counting scales offers the user three displays with different information. Thus, all the parameters – total weight, the piece weight and the number of pieces – are visible at a glance.

Another difference is the numeric keypad with the input keys for the numbers 0 ... 9, which provide fast and convenient value input as well as e.g. the following functions:

- Free adjustable reference piece number
- Direct input of the piece weight
- Summing function
- Direct input of the tare weight
- input of the target piece number / quantity

The process with this counting scales looks like this:

In the first step, the user must set the piece weight in the scales.

For this, the counting scales offer two options:

1. With the help of the reference quantity. The user places e.g. 18 pieces on the scales, press the reference piece number key and enters the number 18 using the input keys.

2. Direct input of the piece weight. If the piece weights have already been determined (see above "average piece weight"), this weight can be entered directly with the help of the number keys.

The count is then immediately visible on the three displays of the counting scales in the following order:

Total weights / unit weight / piece number (quantity)

 

If several batches of a product are counted, a total number of pieces can be determined by summing the individual counts.

Since the pieces to be counted are usually stored and transported in an overpackaging, the net weights must be determined for the counts. The net weight is therefore the pure weight of the pieces to be counted without the packaging.

The counting scales offer the possibility of entering the tare weight of the packaging using the number keys. In this case, unpackaging of the parts to be counted is not necessary anymore, if the tare weight is known.

Another interesting function regarding piece counting is the entering of the target quantity. After the registered number of pieces has been reached, an acoustic signal is given.

But even in case of these types of scales there are differences. The differences are determined and characterized by the extent of the individual functions. In the simpler counting scales, the input of data such as e.g. piece weight / tare weight / target piece number is carried out by the user. In the more complicated models of the counting scales it is possible to create databases which the user can access. This can be possibly done by scanning the item number. Another possibility is the communication of the counting scales with an inventory management system, where the required data can be retrieved and also the data can be stored after a finished counting.

Therefore, it is very important to clarify in advance how the working process with the counting scales should be arranged in order to carry out the time-consuming counting successfully and efficiently.

After the type of scales has been selected, a suitable measuring range must be specified. In general, a compromise has to be made between high resolution and high measuring range. Thus, scales with a higher, maximum weighing range have a lower resolution compared to the scales with a smaller weighing range.

Therefore, before purchasing a counting scale, the lightest piece to be counted must be determined. This piece weight should not be below the resolution of the counting scales, in order to allow a reliable measurement.

Example: If the lightest piece to be counted is 0.2 g, then the scales with min. 0.2g resolution should be used.

Based on this piece weight, the resolution of the scales can be determined, and there are different weighing ranges depending on the price range.

Finally, it should be considered what further steps after the count should be taken. Is it sufficient if the number of pieces only appears on the display of the counting scales or should the number of pieces with the indication of the article number be printed on adhesive labels or, if necessary, stored? These possibilities of data processing differ from one model of the counting scales to another and should be considered, before making the choice.