Level I Questions Mass Spectrometer Testing Method

A vapor is best defined as:

• water in a test system
• a substance which, though present in the gaseous phase, exists as a liquid at room temperature
• a substance in the gaseous state whose temperature is above its critical temperature
• a substance in the liquid state whose temperature is below its critical temperature

Gage pressure is:

• the harmonic pressure within a gage
• atmospheric pressure plus absolute pressure
• the difference between absolute and atmospheric pressure
• a sum of the partial pressures of air at standard temperature and pressure

All leak testing methods are dependent upon;

• barometric pressure
• gas or liquid flow
• mass spectrometer analysis
• mean free paths of helium flow

A type of virtual leak caused by the slow release of absorbed or entrapped tracer gas in a helium mass spectrometer vacuum system is a:

• hang-up
• condenser
• getter
• molecular leak

The sensitivity of a mass spectrometer leak detector system is the mass flow rate of tracer gas:

• that gives a maximum measurable signal
• that gives a minimum measurable signal
• at standard temperature and pressure
• in a leak

As the required sensitivity of a leak test increases, the cost of the test:

• decreases
• remains constant
• increases
• decreases exponentially

Which of the following can be considered a major class of mass spectrometer leak testing?

• static test
• dynamic test
• both a and b
• none of the above

Outgassing is defined as:

• the removing of the free gas from a system
• the spontaneous evolution of gas from a material in a vacuum
• the spontaneous conversion of a gas to a liquid
• removing the vacuum

Vacuum bake-out is defined as the:

• heating of a system to remove water vapor
• degassing of a vacuum system by heating
• use of a halide torch to boil off liquids in the system
• heating of liquid nitrogen in the cold trap by condensable vapors

A material that is included in a vacuum system for removing gas by absorption is called:

• a getter
• a collector
• an orifice
• a molecularizer