Re: [bika-dev] Sieving calculation

[lemoene <le...@bi...>]

  Hi Didier

> Sorry for my english, I'm a french speaker.

No prob

> In our laboratory, we have analysis on granulate (limestone) and we 
> give results in 2 types; >5mm and <5mm

I encounter these sieve stacks before in mining and soil labs

>
> Attention: the order of the sieves is important, because it's like 
> this we work.
>
> First type: < 5mm:
>
> sieves
> 	Weight in g
> 	Result in %
> 0.063mm
> 	3.17
> 	87.32
> 0.090 mm
> 	0.98
> 	96.08
> 0.100 mm
> 	0.61
> 	97.56
> 0.125 mm
> 	0.16
> 	99.36
> 0.200 mm
> 	0.01
> 	99.96
> solde (rest)
> 	25.00
> 	
>
>
>     * 25g is the weight of product we put on the first sieve (0.063 mm)
>     * In this type of results, the calculation is ((25g - weight on
>       each sieve)/25)*100
>     * There is no result for the rest
>

I suggest the following

    1. Create a calculation (see Calculations
    <http://bika3.bikalabs.com/knowledge-centre/manual/bika-3-user-manual/setup-and-configuration/calculations>
    in the manual): First specify an interim field for the weight, say
    'weight' and then a calculation, e.g. ((25-[weight])/25)*100

    2. Create an analysis service (manual: Analysis Services
    <http://bika3.bikalabs.com/knowledge-centre/manual/bika-3-user-manual/setup-and-configuration/analysis-services>)
    for each of the each of the screen sizes, e.g Granulate % 0.063 mm,
    Granulate % 0.090 mm, etc. This way the analyses will also sort in
    the correct order.

    3.  Use the calculation you created for each new Analysis Service -
    select it on the AS' Method tab

The system should now take care of the extra columns etc. in the forms 
where the calculations are required

    4.  Since you are always goin to select these together when creating
    ARs, you might want to include all of these in a Analysis Profile 
    so they can be selected together with 1 click only. Analysis
    Profiles
    <http://bika3.bikalabs.com/knowledge-centre/manual/bika-3-user-manual/setup-and-configuration/analysis-profiles>

> The second type of results > 5mm is like this:
>
> sieves
> 	Weight in kg
> 	Result in %
> 25.0 mm
> 	2.181
> 	56.467
> 20.0 mm
> 	1.62
> 	24.132
> 12.50 mm
> 	1.084
> 	2.495
> 7.10 mm
> 	0.107
> 	0.359
> solde (rest)
> 	0.018
> 	
>
>
> In this type of results, the calculation is like this; for example at 
> 12.50mm:
>
>     * we calculate the total weight: 5.01 kg
>     * at 12.50 mm the result is: ((5.01 - (1.084+1.62+2.181)/5.01))*100
>     * it's the same for each sieve and there is no result for the rest
>

Same as the above, but you'll have to include the dependent results by 
referencing their keywords which you have to assign when you create the 
new Analysis Services, say '20mmweight' & '25mmwight' for the above. 
Then the above example's calculation would become: ((5.01 - ([weight] 
+[20mmweight]+[20mmweight])/5.01))*100.

If your starting weight is variable, add an interim field for that too

---------8<-----------------------------------

*NB. *I am looking forward to your feedback and if it all works, we can 
add the final calculations to our system configuration files and include 
it in future releases

> Actually, in our software, we say that for this equipment we use this 
> type of calculation

Please could you elaborate? One could define each sieve as an instrument 
and then link each the analysis service to  its correct sieve

Bests
lemoene