Разные результаты на одних исходных данных

float CalcClouds(const float r500, const float r700, const float r850)
{
    float N1 = 0.0172 * r500 - 0.43;
    float R = (r500 + r700) * 0.005;
    float N2 = 2 * R - 0.7;
    R = (r850 + r700) * 0.005;
    float N3 = 3.25 * R - 1.95;
    float Res = 1.0 - (1.0 - 0.2 * N1) * (1.0 - 0.4 * N2) * (1.0 - 0.5 * N3);
    Res = (Res < 0.0) ? 0.0 : round(Res * 11.56); //10
 
    return (Res);
}

S_DataFormat __fastcall TMainForm::Get_Data_O(
    int Src, TDateTime DT, int LAT, int LON)
{
    int MD[3] = { 878969332, 878969532, 878969682 };
    String txt[3] = { "-RH500", "-RH700", "-RH850" };
    float RH[3];
    int Q = 0;
    TDateTime UDT = TDateTime(80000);
    S_DataFormat OBL, Rez;
 
    AQ_Get_Data->Close();
    AQ_Get_Data->SQL->Clear();
    AQ_Get_Data->SQL->Add(
        "SELECT ZNCH, UDT, QUAL FROM Weather WHERE DT = :pDT"); //
    AQ_Get_Data->SQL->Add("AND SOURCE = :pSRC AND ID_MD = :pMD");
    AQ_Get_Data->SQL->Add("AND LON = :pLON AND LAT = :pLAT");
    AQ_Get_Data->Parameters->ParamByName("pDT")->Value = DT;
    AQ_Get_Data->Parameters->ParamByName("pSRC")->Value = Src;
    AQ_Get_Data->Parameters->ParamByName("pLAT")->Value = LAT;
    AQ_Get_Data->Parameters->ParamByName("pLON")->Value = LON;
 
    for (int i = 2; i >= 0; i--) {
        AQ_Get_Data->Parameters->ParamByName("pMD")->Value = MD[i];
        AQ_Get_Data->Open();
        if (AQ_Get_Data->RecordCount > 0) {
            RH[i] = AQ_Get_Data->FieldByName("ZNCH")->AsFloat;
            UDT = min(UDT, AQ_Get_Data->FieldByName("UDT")->AsDateTime);
            Q = max(Q, AQ_Get_Data->FieldByName("QUAL")->AsInteger);
        } else {
            OBL.Text = txt[i];
            goto GDO_END;
        }
        AQ_Get_Data->Close();
    }
    OBL.udt = UDT;
    OBL.qual = Q;
    OBL.znch = CalcClouds(RH[0], RH[1], RH[2]);
GDO_END:
    Rez = OBL;
    return (Rez);
}

void __fastcall TMainForm::Select_Data_O(int Src, TDateTime DT, int LATn,
    int LATk, int LONn, int LONk, int RezLat, int RezLon)
{
    int max = Select_LatLon(LATn, LATk, LONn, LONk, RezLat, RezLon);
 
    if (max == 0)
        return;
 
    QrWrt->Close();
    QrWrt->SQL->Clear();
    QrWrt->SQL->Add(
        "INSERT INTO " + Tbl_Calc->TableName +
        " VALUES (:pDT, :pLAT, :pLON, :pZNCH, :pUDT, :pQUAL, 0, :pX, :pY, :pTXT, 0)");
    QrWrt->Parameters->ParamByName("pDT")->Value = DT;
 
    int LAT, LON;
    S_DataFormat OBL;
    AQLAT->First();
    float i = 0.0;
 
    while (!AQLAT->Eof) {
        QrWrt->Parameters->ParamByName("pLAT")->Value = LAT =
            AQLAT->FieldByName("LAT")->AsInteger;
        QrWrt->Parameters->ParamByName("pY")->Value =
            LatToY(LATn, LATk, LAT, ImageMF->Height);
        AQLON->First();
        while (!AQLON->Eof) {
            if (DataPrep->CheckTerminated())
                return;
            StatBar->SimpleText =
                "Выполнено " + FloatToStrF(i / max, ffFixed, 3, 2) + "%";
            QrWrt->Parameters->ParamByName("pLON")->Value = LON =
                AQLON->FieldByName("LON")->AsInteger;
            QrWrt->Parameters->ParamByName("pX")->Value =
                LonToX(LONn, LONk, LON, ImageMF->Width);
            OBL = Get_Data_O(Src, DT, LAT, LON);
            QrWrt->Parameters->ParamByName("pUDT")->Value = OBL.udt;
            QrWrt->Parameters->ParamByName("pQUAL")->Value = OBL.qual;
            QrWrt->Parameters->ParamByName("pZNCH")->Value = OBL.znch;
            QrWrt->Parameters->ParamByName("pTXT")->Value = OBL.Text;
            QrWrt->ExecSQL();
            AQLON->Next();
            i = i + 100.0;
        }
        AQLAT->Next();
    }
    StatBar->SimpleText = "Выполнено 100%";
    Tbl_Calc->Close();
    Tbl_Calc->Open();
}

Select_LatLon(LATn, LATk, LONn, LONk, RezLat, RezLon)