private void UpdatePlotHumid(double t, double d)
        {
            LineSeries lineSeries = Humid.Series[0] as LineSeries;

            lineSeries.Points.Add(new DataPoint(t, d));

            if (lineSeries.Points.Count > config.MaxSampleNumber)
            {
                lineSeries.Points.RemoveAt(0);
            }

            if (t >= config.XAxisMax)
            {
                Humid.Axes[0].Minimum = (t - config.XAxisMax);
                Humid.Axes[0].Maximum = t + config.SampleTime / 1000.0;;
            }

            Humid.InvalidatePlot(true);
        }