```pascal
FUNCTION "PPM O2" : Real
{ S7_Optimized_Access := 'FALSE' }
AUTHOR : 'Author'
FAMILY : 'Function'
NAME : 'Name'
VERSION : 1.0
   VAR_INPUT 
      i_Temp : Real;
   END_VAR

   VAR_TEMP 
      a : Real;
      b : Real;
      c : Real;
   END_VAR


BEGIN
	
	  
	(* classic code: #a :=   0.00353376 ;*)
	#a := REAL#0.00353376;
	(* classic code: #b :=  -0.33438937 ;*)
	#b :=  REAL#-0.33438937;
	(* classic code: #c :=  14.38695088 ;*)
	#c :=  REAL#14.38695088;
	  
	    #"PPM O2" := SQR(#i_Temp) * #a + #i_Temp * #b + #c ; 
	  
	
END_FUNCTION


```