def dew_point_from_db_hr(db_temp, hr, b_press=101325):
    """Dew Point Temperature (C) at Temperature db_temp (C),
    Humidity Ratio hr (kg water/kg air) and Pressure b_press (Pa).
    """
    rh = rel_humid_from_db_hr(db_temp, hr, b_press)
    td = dew_point_from_db_rh(db_temp, rh)
    return td