ARCON2 - Minor Corrections in Output Files
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Background

ARCON2 and ARCON96 output provides the cumulative distribution function (CDF) for X/Q limits 
that are exceeded for averaging periods from 1 to 8 hours (short-term averaging periods) and 
for 12 through 720 hours(long-term averaging periods). These two codes have been erroneously 
printing the same X/Q limits for both short-term and long-term averaging periods. 
This error was apparent in the ARCON2 User’s Guide Example 5 . In the revised version, ARCON2 
code was modified to print the correct X/Q ranges for long-term averaging periods. 

Modification

ARCON2 calculates the lower limits (see LOWLIM values in the .EXT file) for the CDF distribution 
from the maximum centerline X/Q for short-term averaging periods and from a combination of maximum 
centerline and sector-averaged X/Q values for long-term averaging periods. Though the correct values 
were used for CDF generation, the lower limit values for the 4-hour averaging interval was incorrectly 
displayed instead of the limit from 12 hours or any other long-term averaging period in both the .CDF 
and .EXT output files. In the revised version of ARCON2, the X/Q limits printed in the output was 
correctly set for the value associated with the 12-hour averaging period in the .CDF and .EXT files

Testing

The revised ARCON2 executable was tested against the previous version to ensure no other changes 
occurred in calculations and desired output. All test cases from the ARCON2 User’s Guide were 
performed with both the original and revised versions of ARCON2 and the comparison of the outputs 
are documented in a series of PDF documents. There are no differences in outputs between these two 
versions except for the corrected display of X/Q limits in .CFD and .EXT outputs.