public object ConvertBack(object value, Type targetType, object parameter, string language)
        {
            double fromValue = System.Convert.ToDouble(value);
            Tuple <ISensorItem, IGaugeItem> tuple = (Tuple <ISensorItem, IGaugeItem>)parameter;

            if (tuple.Item2.GaugeType == GaugeTypeEnum.TextControl)
            {
                return(fromValue);
            }

            Units fromUnits = (Units)tuple.Item1.SensorUnits;
            Units toUnits   = (Units)tuple.Item2.Units;

            if (fromUnits == toUnits)
            {
                return(fromValue);
            }

            UnitItem fromUnitItem = UnitsConverter.Find(fromUnits);
            UnitItem toUnitItem   = UnitsConverter.Find(toUnits);

            return(UnitsConverter.Convert(toUnitItem, fromUnitItem, fromValue));
        }