The machine factor is the relation between the flow measured with a calibrated leak directly linking with the leak detector and the same leak directly linking with the product tested and placed in the chamber for measurement.

A test leak device (10) comprising a gas-filled container (12) and a capillary (18) extending through the container wall is characterized in that the gas consists to at least 10% of atmospheric air (20).

The machine factor is the relation between the flow measured with a calibrated leak directly linking with the leak detector and the same leak directly linking with the product tested and placed in the chamber for measurement.

the monetary unit is neither a stable nor an international standard

The etalon (12) can be a reflective etalon (29) or in an alternate embodiment (60), can be a transmissive etalon (29).

A size standard, kit including a size standard, method of defining a size standard and method of analysis using a size standard are provided.

The reference standard instrument shall be fully calibrated at yearly intervals in accordance with a national standard.

The reference standard instrument shall be fully calibrated at yearly intervals in accordance with a national standard.

The calibration standard typically includes a calibration standard and a plurality of optical targets.

The reference standard instrument shall be fully calibrated at yearly intervals in accordance with a national standard.

Preparation of the standard polystyrene solutions

variation in length of a gauge block

The third circuit produces a force on each proof mass by which the proof masses are levitated.

Preparation of the external standard solution

Preparation of the internal standard solution