uvdata.dat has the following fixed-width columns:
    NumberWOUDC, Serial, SolarTimeYYMMDD, SolarTimeHHMM, GMTHHMM, MuValue, ZenithAngle, UvIntegral(1), UvIntegral(2), O3, ErrorO3, So2, ErrorSo2, F324, Temperature, Flags, HgError, Aer, ErrorAer.

 1  WOUDC station ID
 2  Brewer instrument serial number
 3  Date (solar time)
 4  Time (solar time)
 5  Time (UTC)
 6  Airmass value
 7  Solar zenith angle (degrees)
 8  Spectrally integrated UV (ACGHI weighting function)
 9  Erythemally weighted UV in  (divided it by 25 to get UV index)
10  Total ozone derived from the spectrum in DU
11  The standard error of total ozone in DU
12  SO2 from the spectrum in DU (0 if below the limit)
13  The standard error of SO2 in DU (99 is SO2 if SO2 below the limit)
14  Clearness index, i.e., UV at 324 nm divided by modeled clear sky sea level UV at 324 nm 
15  Brewer internal temperature (in C)
16  Data quality flag
17  Hg test results (0 if Hg tests prior and after the scan were OK, 1 if cannot check, 2 if one of the two test failed)
18, 19 Aerosol characteristics derived from "long" scan. Reserved for future data products

Samples data line with labelled columns:
  1  2      3       4     5     6    7      8      9    10 11 12 13  14 15   16   17    18  19
 65 15 2004/01/01 07:30 12:51 99.99 90.85  0.01   0.13 303  1  0 99  41 14 000000 1    0.0  0.0