Attach a micron gauge to the male flare end, a gauge to the tee end, and a line from the tee to the pump. Turn the pump on and you will notice the side closest to the pump will be a lot lower than the other.
The WEEKNUM function is used in Excel to return the week number of a specific date in the year (a number between 1 and 54). It has two arguments, the 1st is required and the 2nd is optional: WEEKNUM(serial_number, [return_type]) Serial_number - any date within the week whose number you are trying to find.
WEEKDAY will extract a weekday number, and CHOOSE will use this number to return the nth value in the list. This works because WEEKDAY returns a number 1-7 that corresponds to a given day of the week. With default settings, Sunday = 1 and Saturday = 7.