def saturated_vapor_pressure4(t):
    """Calculate the saturated vapor pressure as described in
    http://www.vaisala.com/Vaisala%20Documents/Application%20notes/Humidity_Conversion_Formulas_B210973EN-F.pdf

    Parameters
    ---------
    t : float
        Temperature [C]

    Returns
    -------
    Saturated vapor pressure [mBar]
    """
    A = 6.116441
    m = 7.591386
    Tn = 240.7263
    return A * 10 ** (m * t / (t + Tn))
