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Spreadsheet CFM numbers HELP!

Posted: Tue Jan 07, 2020 9:03 am
by Roy
Having issues setting up a spreadsheet so that I can measure at say 40 inches of water and have CFM results corrected to another standard (in this case 28". Cannot for the life of me figure out what I'm doing wrong. ](*,)

cell C23 =IF(E110>0,(Choose(D110,$D$72,$D$73,$D$74,$D$75,$D$76,$D$77)*E110)*$H$6, )
(wanting the cell to only show a value if theres data, otherwise all the columns say error when I print it out. Not very professional)
IF(measured percent>0,(Choose (Measured scale, corrected to measured scale 1,2,3,4,5,6)*Measured percent)*Correction factor for desired pressure

E110 is the cell I input the percentage of flow from the meter

D110 is the cell I input the range I am running

D72 through D77 =(($H$4/25)^0.5)*B72 through B77.
((Measured @ pressure/OEM scale pressure)^.5)*oem flowbench 100% numbers

H4 is the cell I specify what the flow is MEASURED at.

B72 through B77 is the OEM flow calibration numbers at 25"

H6 =(H5/H4)^0.5
(Chart pressure/Measured pressure)^.5

H5 is the cell I specify what I want the chart to show flow at.

So in short (or long...)

IF(<Logic>measured percent is greater then 0,<value if true>Choose(<# representing which choice>Flow scale,<Choice 1,2,3 etc is returned, in this case a variation of>((Specified measured pressure/oem chart pressure)^.5)*oem chart flow value at specified scale)*Flow percentage from meter*((Chart pressure/measured pressure)^.5)

When I change the measured at pressure my numbers don't change so I KNOW I have something screwed up but after 3 hours I still have no clue. When someone points it out I know its something with my math cancelling out because I have it wrong.. I also kknow its wrong because below .100 lift I am exceeding the DC by a fair amount, but If I return to my old spreadsheet which I only measured at 28" and charted at 28" It falls back in line. Please be gentle, I am not an expert in this one bit..

Re: Spreadsheet CFM numbers HELP!

Posted: Sat Jan 11, 2020 7:20 pm
by Stan Weiss
I am not sure I understand how it should work. But see if this does it.