Have a problem trying to convert weight and/or metres to OD, I work in the flexible packaging industry coordinating all the trials for the UK & Europe.
I can calculate from an exsisting OD to weight & Metres using the following VBA statement;
RNEW = (PI * ((((NEWI(1) / 1000) / 2) ^ 2) - (((76 / 1000) / 2) ^ 2))) / (Val(Left(MAT, 2)) / 1000000)
Where PI is a constant created by PI = Application.WorksheetFunction.PI()
NEWI() is an array containing, recieved OD, recieved weight, recieved metres .. specifically for this calculation the recieved OD
76 is the internal diameter of the core the material is wound onto
MAT is the gauge of the material recieved.
This works fine, however when I minus the recieved amount from the stock amount and convert it back to OD using
OD = (2 * (Sqr((((TGAUGE / 1000000) * RNEW) / PI)))) * 1000 + ((CORE / 2) ^ 2) / 1000
TGAUGE = Material Gauge : RNEW = Metres : CORE = Core Diamter
there is a discrepencies between the actual measured OD and the calculated one.
Any Help would be appreciated, especially if somone knows the right calculation for this.
Windows XP (SP3) - Office Excel (11.8169.8172) SP3 - VBA 6.5
November 30, 2009 10:41 AM
December 4, 2009 9:55 PM