Empower Not calculating Custom field.

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Hi, this is driving me mad so I am hoping some of you experienced members will have seen this before and can just point me in the right direction.

I have a run, where the results for samples in each bracket are calculated with reference to the bracketting check standards.There is always a summarise CF's function at the end of the SS

for each check standard a ratio of analyte to istd is required.
this is fine except the last check standard ( coincidentally the last injection in the run) which doesnt calculate at all.
The Custom field equation is C8..(Response)
the same field is calculated for all earlier check stds (1-7) using the same format.
this has the knock on effect that the average bracketting standard is the value of C7, the preceding check divided by 2, as C8 gives no result

I have no clue why this is the case, any help greatly appreciated.
ta
Its the syntax of your formula. If you dont specify an injection, Empower will only return the most recent result before the current result. So six sets of standards with labels of C1 to C6. In a formula of C?..(Response), Empower will ignore the final C label in the data set you are processing.

Change your formula to C8.%.(Response) and reprocess and this will work. The % symbol represents "all of the injections" and can be used for all samples and channels too, and this means that Empower will see and include all samples where the injection is included, it doesnt matter if its a single injection or 100 injections, the % symbol covers all scenarios.
Hi, thanks for the help. defininately a step in the right direction.
addition of the % to the formula does then give a value for the C8 check standard response custom field.
unfortunately the calculation of the average of this and the previous check standard still returns a value that is roughly half what it should be.
As in it seems to calculate the average ( sum of both responses/2) not taking the last injection into account.
Any ideas gratefully recieved.
thanks again
Phill

Update.. after 7 hours of tweaking I have realised that if I process from the result set. With no recal and using the existing integration ( so pretty much just doing recalculation; All the CF's calculate correctly and the results match those calculated manually from the same data.
Not sure what that tells me, but if worst cones to worst then it's a way forward.
If anyone knows a more streamlined/elegant way of doing this please let me know.
thanks
Whats the custom field formula for your standard average calculation? And how are these 2 standards labelled in sample set? You shouldnt have to process result sets like that for a basic calculation.
The check standards CF's are set to return a response value.. eg C8.%.(Response) .Checks standards have labels C1 to C8. The two check standards which bracket a particular set of samples are averaged to give another CF. Which is then used to generate a correction factor ( Comparing the result by with the middle calibration standard) another CF.
The results are also corrected for LOD via a further CF.
I am stuck with the slightly idiotic method of calculation as the method already exists and is registered with the regulator, so I can't really change anything. I am trying to validate this so we can move from manual calculation to automated calcs and reporting.
To be honest it's has taken so long to get to this point that I suspect I will just get them to process twice as at least then I can be sure the results will validate against manual calculation.
I know what you mean about methods being locked down. Sometimes its easier to make a complicated calculation that it is to change an established, inefficient method!
Reading your post, I suspect the CFs only generate after processing a result set because it requires the calibration curves be generated in full before you apply any CFs to them, so any CFs with Amount field in them can be tricky, depending on how your brackets are set up. I know for instance that creating multiple calibration curves in a sample set will affect your CFs if Amount is included, which would point to why only reprocessing a result set would work.

A few things to check, like your search order is Result Set Only, and sample/peak type set to All.
If that's ok, try naming your CFs in Alphabetical Order- summary CFs in particular require this to operate in the correct and logical order. So taking your first CF call it something like A_CF_One (just make sure A is first letter), and formula is (C7.%.(Response)+C8.%.(Response))/2.
Call your second CF B_CF_Two and If I understand you, you are using the result for CF1 as correction factor for your samples? So if you label each sample as U followed by something, eg U1, U2, U0101 etc etc then the formula for B_CF_Two (keeping the same search order etc as first one) is:

U%.%.(Amount)*A_CF_One. Then if you need to further adjust this for LOD, you could use the CConst1 field of your processing method as this LOD value. I presume your are checking B_CF_Two against this value so the 3rd CF of C_CF_Three could be a peak bool CF with formula like GTE(B_CF_Two,CConst1) and return either text like Pass/Fail or a field itself if you pick Use as Field.

Hope this helps a bit.
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