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sandramac

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Performing Calculations for Relative Humidity and Heat Index

Hello, needing some help here.

Cell Sheet5 B13 and C13 has values that represent temperature and dewpoint in Fahrenheit.  I need to convert each value into Celsius, the formala is 5/9*(Temp-32).  Then for the first value I need to use this formula 6.11*10.0**(7.5*Tc/(237.7+Tc)), where Tc is the value.  Then for the second value I need 6.11*10.0**(7.5*Tdc/(237.7+Tdc)), where Tdc is the second value.  Finally I need to divide the number from the second equation by the number in the first equation and times it by 100.

Finally, I need to computer =16.923+(Temp*1.85212*(10^-1))+(5.37941*RH)-((Temp*RH)*1.00254*(10^-1))+((Temp^2)*9.41695*(10^-3))+((RH^2)*7.28898*(10^-3))+((Temp^2)*RH*3.45372*(10^-4))-(Temp*(RH^2)*8.14971*(10^-4))+((RH^2)*(Temp^2)*1.02102*(10^-5))-((Temp^3)*3.8646*(10^-5))+((RH^3)*2.91583*(10^-5))+(RH*(Temp^3)*1.42721*(10^-6))+((RH^3)*Temp*1.97483*(10^-7))-((RH^2)*(Temp^3)*2.18429*(10^-8))+((RH^3)*(Temp^2)*8.43296*(10^-10))-((RH^3)*(Temp^3)*4.81975*(10^-11)).  Temperature is the original Fahrenheit value and RH is what we calculated above.


Trying to shoot for some type of function as I will need to use this to calculate multiple cells.  Thanks in advance for you help.
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David Johnson, CD
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replace the ** with ^
ee29019572.xlsx
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sandramac

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David, thanks for the help.  Still need some assistance.  In your example, you have temperature and relative humidity as the given numbers.  However, temperature and dew point are the given values, not the relative humidity.  So I need to convert both temp and RH to Celsius, then use the formula  6.11*10.0**(7.5*T/(237.7+T)) for both values, T would the respective number that we got, when we converted the temp.  Then divide the number from the second equation by the number in the first equation and times it by 100.  Once we get that number, that is the RH,

then plug the values into this formula 16.923+(Temp*1.85212*(10^-1))+(5.37941*RH)-((Temp*RH)*1.00254*(10^-1))+((Temp^2)*9.41695*(10^-3))+((RH^2)*7.28898*(10^-3))+((Temp^2)*RH*3.45372*(10^-4))-(Temp*(RH^2)*8.14971*(10^-4))+((RH^2)*(Temp^2)*1.02102*(10^-5))-((Temp^3)*3.8646*(10^-5))+((RH^3)*2.91583*(10^-5))+(RH*(Temp^3)*1.42721*(10^-6))+((RH^3)*Temp*1.97483*(10^-7))-((RH^2)*(Temp^3)*2.18429*(10^-8))+((RH^3)*(Temp^2)*8.43296*(10^-10))-((RH^3)*(Temp^3)*4.81975*(10^-11)).  Temperature is the original Fahrenheit value and RH is what we calculated above.
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byundt
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Thanks, your functions helped me out tremendously