
 By specifying SF=F, PGM=MEAN will generate the flow weighted average
 for each time period for which statistics are requested.

 PGM=MEAN uses the following formula when calculating the flow weighted
 average.


                               --
                               \
                               /   (FLOW * CONCENTRATION)
                               --
     FLOW WEIGHTED AVERAGE = ------------------------------
                               --
                               \
                               /   FLOW
                               --


 Example:
 -------


            Sample   Concentration  X  Flow   =  Weighted Product
            ------   -------------     ----      ----------------

              1            5        X    1    =         5
              2            4        X    6    =        24
              3            1        X   ( )   =       ( )  Missing !
              4            8        X    3    =        24
             --           --            --             --
              4           18            10             53


                                       18
                    STRAIGHT AVERAGE = -- = 4.5
                                        4


                                       53
               FLOW WEIGHTED AVERAGE = -- = 5.3
                                       10


      In addition, a valid flow parameter must be specified, via the P=
 keyword, within every group of 10 parameters for which the
 flow-weighted average is to be calculated.

      The PM=, PARF=, PARH1=, PARH2 and PARU= keywords may be used to
 specify substitute flow parameters, in the case that the flow parameter
 initially requested is not present.

      In the event that a flow value cannot be identified for the sample
 at hand, the sample is ignored in the calculation of any flow-weighted
 average.

 Example - using flow parameter 60
 -------

 PGM=MEAN,PURP=TEST,
 A=EXAMPLE,S=SEMINAR01,SF=F,
 P=60,
 P=1027,P=1042,P=1045,P=1051,P=1056,P=1090,P=1092,P=31616,P=31615,
 P=60,
 P=1010,P=1020,P=1032,P=1034,P=1046,P=7190,P=71851,P530,P=618,
 P=60,
 P=610,P=671,P=680,
