Help required - EJMU calculation method

[lemental]

I'm in the process of creating my own excel calculator as I can add convenient features.  However, I'm having a bit of a brain freeze.

All was going well until I put in a line for the addition of Vodka/TPA.

The example I'm using is a 100% PG nic base.

If we look at EJMU, adding vodka to a mix changes the VG% content as well as the PG% content.

I don't see how this works as if I want, let's say 10ml of a 30% VG juice, there should be 3ml VG in it.

I don't think it's quite as simple as the VG% being reduced by the % of Vodka.  There seems to be a little more to it.

Could anyone please explain how the addition of Vodka/PGA affects percentages in the formula EJMU uses?

[lemental]

What it looks like it's doing it splitting the % of Vodka in equal proportions and taking it off the figures for:

1) The additional PG % to be added (not including anything in the nic base)

and

2) The VG % to be added.

This is strange.  Surely the Vodka & added should take the amount of PG in the nic base into account when calculating the added PG % and the VG % should remain stable.

(If I were to use a nic base containing VG then in that case, the % VG addition should alter in relation to the % vodka but in this case I'm using 100% PG nic)

-edit- upon further testing, EJMU seems to reduce the Vodka % equally between PG% to add and VG% to add, irrespective of the PG/VG ratio of the nic base.



* I do appreciate that the amount of vodka normally used in recipes that contain it is a small percentage so won't have a huge effect on the final mix but either I'm doing something wrong or EJMU calculates in a way that confuses me.

[Perpetua]

I don't take any dilution into account must admit Lemental . . . I just treat my diluted VG, as VG. As you say the amount used isn't really significant for the average home mixer to make a difference to the final mix.

So I don't clutter up my thinking/calculations with the specifics of it.

Sorry not to be more useful.

[lemental]

Thanks P,

From what I understand, normally AG (VG thinned with alcohol or distilled water) is not normally taken into account when calculating mixes. Strictly speaking from a calculation point of view, if you wanted figures to be absolutely 100.000% accurate, it ought to be.

The way Vodka/PGA seems to be treated in EJMU as I detailed in my second post seems to be a little odd. It doesn't make much difference if you experiment with an EJMU recipe containing small percentages of Vodka/PGA but if using the calculator and putting less 'real world' examples of much higher percentages of Vodka/TPA, either the calculation method is odd or I am doing something wrong with my own calculations.

If I omit the Vodka/PGA figures, the calculator works well To be honest I haven't used it vodka in my mixes so far but would like the provision for it in the calculator. It's just that I've been using EJMU to verify my calculations by using examples and with the codka/PGA they've not been matching.

[Roger]

If you use 10% vodka/DW in a 10ml recipe, that is 1ml. Therefore the amount of dilutant pg/vg has to be reduced by 1ml to allow for this without reducing the required nic content. If you are making this at 70/30, the 9ml will be at 70/30. Your actual final 10ml will be about 65/25 because of the 10% vodka/dw. Just do as Perps suggests.

[lemental]

Aug 5, 2013 14:17:01 GMT Roger said:

If you use 10% vodka/DW in a 10ml recipe, that is 1ml. Therefore the amount of dilutant pg/vg has to be reduced by 1ml to allow for this without reducing the required nic content. If you are making this at 70/30, the 9ml will be at 70/30. Your actual final 10ml will be about 65/25 because of the 10% vodka/dw. Just do as Perps suggests.

I understand this Roger.  When looking at EJMU it appears, using your example, that the reduction of 1ml is split 50/50 between added PG% and VG% irrespective of the PG/VG ratio whereas it should be split between total PG and VG ratios.  I'm only really using EJMU to check the figures in my spreadsheet for my sanity  I could just remove Vodka/PGA from the equation as the figures are small and the end mix will be as accurate as needs be but I really want my calculator to be precise.

The way my calculator works is:

I plug in:

ml of final juice
strength of final juice in mg/ml
PG ratio of final juice

nic strength in mg/ml
% of PG in the nic
PG% of final juice

then I select my flavours from dropdown boxes and plug in the percentages of each component.

After doing this, it fills in everything else: volume of component to be added, weight, density, bulk cost, cost per ml.  Then it calculates the totals.

[Roger]

Aug 5, 2013 14:38:23 GMT lemental said:

Aug 5, 2013 14:17:01 GMT Roger said:

If you use 10% vodka/DW in a 10ml recipe, that is 1ml. Therefore the amount of dilutant pg/vg has to be reduced by 1ml to allow for this without reducing the required nic content. If you are making this at 70/30, the 9ml will be at 70/30. Your actual final 10ml will be about 65/25 because of the 10% vodka/dw. Just do as Perps suggests.

I understand this Roger.  When looking at EJMU it appears, using your example, that the reduction of 1ml is split 50/50 between added PG% and VG% irrespective of the PG/VG ratio whereas it should be split between total PG and VG ratios.  I'm only really using EJMU to check the figures in my spreadsheet for my sanity  I could just remove Vodka/PGA from the equation as the figures are small and the end mix will be as accurate as needs be but I really want my calculator to be precise.

The way my calculator works is:

I plug in:

ml of final juice
strength of final juice in mg/ml
PG ratio of final juice

nic strength in mg/ml
% of PG in the nic
PG% of final juice

then I select my flavours from dropdown boxes and plug in the percentages of each component.

After doing this, it fills in everything else: volume of component to be added, weight, density, bulk cost, cost per ml.  Then it calculates the totals.

It is.  It has to be split 50/50 to maintain the ratio in the 9ml.  You can be too precise, a lot of commercial mixers use EJMU, they are happy, so am I.

[lemental]

I do like and use EJMU too but I'm just trying to understand how it calculates.   I'm still unsure as to why it should be split exactly 50/50 irrespective of final ratios.

I think I am either not understanding final ratios or just trying to be too precise!!

[fred]

Aug 5, 2013 15:01:22 GMT lemental said:

I do like and use EJMU too but I'm just trying to understand how it calculates.   I'm still unsure as to why it should be split exactly 50/50 irrespective of final ratios.

I think I am either not understanding final ratios or just trying to be too precise!!

Because that's the way it's coded 

If you think about it, if you add ANY vodka, you can not possibly achieve a 60/40 or 70/30 (or any other) ratio, as a certain percentage would be vodka,so you would end up with say : 70/25/5 PG/VG/Vodka. So that is not precise either

Your best bet, would be to dilute your VG however you see fit, and forget about dilutents in your spreadsheet, as Perpetua said above.
For the sake of being precise, then call it AVG/VVG rather than VG

[lemental]

Thanks fred - between yourself, Perpetua and Roger I've decided that it's too much hassle

I think I'll go with your suggestion and not incorporate Vodka/PGA into the calculator for the moment. That makes my life a lot easier!! 

Thanks all for your input