ÖNORM EN 1518

This European Standard specifies terms and procedures for the characterization of mass spectrometer leak detectors (MSLD). It is not intended to give a complete set of specifications for an acceptance test but a description of procedures that can be used without particular cali bration equipment. An MSLD has an integral high vacuurn system for maintaining the sensing element (mass spectrometer) at low operating pressure and for establishing a partial pressure related to the incoming gas flow. This pressure is measured quantitatively by the mass spectrometer. Such instments are able to selectively measure the flow of a tracer gas. In most cases the tracer gas will be heliurn, flowing dout of an object through a leak. The methods described in this standard are applicable without restrictions to helium as the tracer gas. For other gases, additional precautions may be necessary.