A method of leak testing a device under test comprising the steps of: a) filling the DUT with a fluid to a predetermined pressure using a first regulator R2 and first valve V1 disposed in series between a source of the fluid and the DUT via a first process sequence comprising a first set of characteristics; b) measuring with a flow controller F1 a measured flow waveform via a second process sequence comprising a second set of characteristics; and c) calculating with a microprocessor a leak rate for the DUT in dependence upon at least the measured flow waveform, wherein at least one of the first set of characteristics and the second set of characteristics were established using a process comprising the steps of: (i) automatically operating a leak test system comprising at least the absolute test pressure sensor P1 measuring the fluid pressure in proximity to the DUT, the flow controller F1 for controlling fluid provided to the DUT, and a controller processing the output of the absolute test pressure sensor P1 to generate a setting for the flow controller F1; (ii) automatically executing a predetermined subset of test sequences of a plurality of test sequences with the leak test system; (iii) storing in a memory associated with a computer a plurality of measurements taken during each test sequence of the predetermined subset of test sequences of a plurality of test sequences; (iv) automatically establishing an equivalent electrical circuit model of the leak test system and DUT in dependence upon at least the plurality of measurements; and (v) automatically determining in dependence upon a predetermined portion of the plurality of measurements at least one characteristic of a plurality of characteristics, each characteristic relating to performing a leak test to a predetermined specification and established in dependence upon the equivalent electrical circuit model. a) filling the DUT with a fluid to a predetermined pressure using a first regulator R2 and first valve V1 disposed in series between a source of the fluid and the DUT via a first process sequence comprising a first set of characteristics; b) measuring with a flow controller F1 a measured flow waveform via a second process sequence comprising a second set of characteristics; and c) calculating with a microprocessor a leak rate for the DUT in dependence upon at least the measured flow waveform, wherein at least one of the first set of characteristics and the second set of characteristics were established using a process comprising the steps of: (i) automatically operating a leak test system comprising at least the absolute test pressure sensor P1 measuring the fluid pressure in proximity to the DUT, the flow controller F1 for controlling fluid provided to the DUT, and a controller processing the output of the absolute test pressure sensor P1 to generate a setting for the flow controller F1; (ii) automatically executing a predetermined subset of test sequences of a plurality of test sequences with the leak test system; (iii) storing in a memory associated with a computer a plurality of measurements taken during each test sequence of the predetermined subset of test sequences of a plurality of test sequences; (iv) automatically establishing an equivalent electrical circuit model of the leak test system and DUT in dependence upon at least the plurality of measurements; and (v) automatically determining in dependence upon a predetermined portion of the plurality of measurements at least one characteristic of a plurality of characteristics, each characteristic relating to performing a leak test to a predetermined specification and established in dependence upon the equivalent electrical circuit model. (i) automatically operating a leak test system comprising at least the absolute test pressure sensor P1 measuring the fluid pressure in proximity to the DUT, the flow controller F1 for controlling fluid provided to the DUT, and a controller processing the output of the absolute test pressure sensor P1 to generate a setting for the flow controller F1; (ii) automatically executing a predetermined subset of test sequences of a plurality of test sequences with the leak test system; (iii) storing in a memory associated with a computer a plurality of measurements taken during each test sequence of the predetermined subset of test sequences of a plurality of test sequences; (iv) automatically establishing an equivalent electrical circuit model of the leak test system and DUT in dependence upon at least the plurality of measurements; and (v) automatically determining in dependence upon a predetermined portion of the plurality of measurements at least one characteristic of a plurality of characteristics, each characteristic relating to performing a leak test to a predetermined specification and established in dependence upon the equivalent electrical circuit model.