{======================================================================
WINKLER: VARIOUS A-D CARD SUBROUTINES FOR DOTCAL
=======================================================================

=======================================================================
Revision 0 21-MAY-94: Initial release
=======================================================================}

{$I+}     { enable automatic I/O error traps }
{$R+}     { enable range checking }
{$N+}     { 8087 mode }

unit WINKLER;

{----------------------------------------------------------------------}
interface
{----------------------------------------------------------------------}

FUNCTION DOConc(     {calc O2 conc in mg/l}
                     Sample      :real {ml vol of 0.01 N sodium thio added}
                     )           : real; {returns DO in mg/l}

{----------------------------------------------------------------------}
implementation
{----------------------------------------------------------------------}

const                       {all volumes in ml}
    N         = 0.01;       {normality of sodium thiosulfate solution}
    blank     = 0.00;       {adjustment for errors in thiosulfate solution}
    B         = 300.0;      {DO bottle volume}
    Reagents  = 2.00;      {volume of reagents added to fix DO bottle}
    S         = 50.0;       {volume of sample with drawn for titration}
    VolSTP    = 22.414689; {volume of gas at STP, liters}
    O2molewt  = 31.988;    {molecular weight of oxygen gas}

var
    DO_       : real;       {DO concentration in ml/l}

{======================================================================}
{ FUNCTION DOConc }
{ Return DO concentration in mg/l }
{======================================================================}
function DOConc;

begin
DO_: = N * (Sample-blank) * (B/(B-Reagents)) * 5.6 * 1000/S;
DOConc := DO_ * O2molewt/VolSTP; {convert ml/l to mg/l}
end;
{-----------------------------------------------------------------------}
end.
{WINKLER ends}