Methods for calculating the coverage interval based on the Flatten-Gaussian distribution

The paper presents numerical and analytical methods for calculating the measurement uncertainty. The methods are based on the Flatten-Gaussian distribution, which is a convolution of rectangular and normal distributions. This distribution represents the possible values associated with the measurand. The methods maybe used when model of the measurand is a linear or a linearized mathematical function, and the input quantities of the model characterizes by the Student's, normal, rectangular, triangular and trapezoidal distributions. The article presents the numerical examples of a use of proposed method.