def delta_cdf(self, d_min, d_max, n=None):
        r'''Computes the difference in cumulative distribution function between
        two particle size diameters.
                    
        .. math::
            \Delta Q_n = Q_n(d_{max}) - Q_n(d_{min}) 
                    
        Parameters
        ----------
        d_min : float
            Lower particle size diameter, [m]
        d_max : float
            Upper particle size diameter, [m]
        n : int, optional
            None (for the `order` specified when the distribution was created),
            0 (number), 1 (length), 2 (area), 3 (volume/mass),
            or any integer, [-]

        Returns
        -------
        delta_cdf : float
            The difference in the cumulative distribution function for the two
            diameters specified, [-]
        
        Examples
        --------
        >>> psd = PSDLognormal(s=0.5, d_characteristic=5E-6, order=3)
        >>> psd.delta_cdf(1e-6, 1e-5)
        0.9165280099853876
        '''
        return self.cdf(d_max, n=n) - self.cdf(d_min, n=n)