SCL露点温度计算

FUNCTION FC500 : VOID
TITLE = '根据温湿度计算露点温度及含值'
VERSION: '1.0'
AUTHOR: 'Hans.Hou'
NAME: Subroutine
FAMILY: FC

VAR_INPUT
TT,TH:REAL; //TT---干球温度(即我们平常所说的温度);TH---相对湿度
END_VAR
VAR_OUTPUT
LT,H:REAL; //LT---露点温度，H---含值
END_VAR
VAR_TEMP
//LC1,LC2,LC3,LC4:REAL;
//LC5,LC6,LC7:REAL;
LC8,LC9,LC10,LC11:REAL;
LC12,LC13,LC14:REAL;
LC15,LC16,LC17,LC18:REAL;
T,PQ,PQB,LE,LA,P,D:REAL;
END_VAR
//LC1:=-5674.5359;
//LC2:=6.3925247;
//LC3:=-0.9677843*10**-2;
//LC4:=0.62215701*10**-6;
//LC5:=0.20747825*10**-18;
//LC6:=-0.9484024*10**-2;
//LC7:=4.1635019;
LC8:=-5800.2206;
LC9:=1.3914993;
LC10:=-0.04860239;
LC11:=0.41764768*10**-4;
LC12:=-0.14452093*10**-7;
LC13:=6.5459673;
LC14:=6.54;
LC15:=14.526;
LC16:=0.7389;
LC17:=0.09486;
LC18:=0.4569;
P:=101325;
LE:=2.718281828;
// T=273.15+TT
T:=273.15+TT;
// PQB=LE**(LC8/T+LC9+LC10*T+LC11*T**2+LC12*T**3+LC13*Ln(T))
PQB:=LE**(LC8/T+LC9+LC10*T+LC11*T**2+LC12*T**3+LC13*Ln(T));
// PQ=TH*PQB
PQ:=TH*PQB;
// LT=-35.957-1.8726*LN(PQ)+1.1689*LN(PQ)**2
LT:=-35.957-1.8726*LN(PQ)+1.1689*LN(PQ)**2;
//D:=622*PQ/(P-PQ)
D:=622*PQ/(P-PQ);
//H:=1.01*TT+0.001*D(2500+1.84*TT);
H:=1.01*TT+0.001*D*(2500+1.84*TT);
END_FUNCTION

DATA_BLOCK DB500

STRUCT
TT:REAL;
TH:REAL;
LT:REAL;
H:REAL;
END_STRUCT
BEGIN

END_DATA_BLOCK

FUNCTION FC501 : VOID
TITLE = '调用子程序'
VERSION: '1.0'
AUTHOR: 'Hans.Hou'
NAME: MAIN
FAMILY: FC
FC500 (TT :=DB500.TT // IN: REAL
,TH :=DB500.TH // IN: REAL
,LT :=DB500.LT // OUT: REAL
,H :=DB500.H
); // VOID

END_FUNCTION