1. A method of modeling a pulsed radar gauge (PRG) including a transceiver coupled by a process connection to a probe installed on a tank, comprising: providing a mathematical model that includes (i) dielectric properties and dimensions of materials used in said process connection, (ii) at least one dimension of said tank (tank dimension), (iii) dielectric characteristics of at least one product material in said tank, and (iv) a length of said probe (probe length); using a processor implementing a stored echo prediction algorithm which utilizes said mathematical model, inputting pulse characteristics including a shape of an input radar pulse launched by a transmitter of said transceiver onto said probe into said mathematical model; generating a predicted echo curve from said mathematical model; comparing said predicted echo curve to an actual echo curve obtained by said PRG, wherein said comparing compares at least one of an amplitude, position, width or number of reflection peaks, and a general shape; generating an alarm when said actual echo curve varies from said predicted echo curve by more than a predetermined amount, and after said alarm, providing guidance for an operator through a set-up or a diagnostic process for said PRG.