HR-IVA® versus IVA®
ORS operates two gas analyzers that use the Mass Spectrometry technique. See the table for performance comparison:
|Mass Spectrometer Type||Quadrupole||TOF • Time Of Flight|
|Full Spectra Every||1 second (typical)||2 ms (can be faster)|
|Calibrated Volumes||0.01cc to 20cc||0.001cc to 20cc|
|DLA Approved Volumes||0.006cc to 20cc||0.0006cc to 20cc|
|Instrument Name||IVA® and HR-IVA®|
|Sample Temperature||100°C Typical (can be set from Room Temperature to 150°C)|
|Sample Mounting||Individual sample mounting. Direct coupling on a Ø6mm O’ring, or enclosure in a metal Mount|
Both instruments operate under Ultra High Vacuum (E-8 torr). When the gas sample is extracted from the cavity of the device, it flows into the chamber under vacuum and measurement happens during this gas flow.
Quadrupole Mass Spectrometer: IVA®
The Quadrupole Mass Spectrometer is a mass filter. All the gas molecules under test are ionized to form ions. All the ions are accelerated and travel through the Quadrupole mass filter. The filter measures one mass at a time and needs to sweep through the mass scale (2 to 160) with different sensitivities. While a mass is measured, the others are ignored. This detector is well suited when there is enough time to perform the various scans. It corresponds to gas volumes >0.01 atm·cc.
TOF (Time Of Flight) Mass Spectrometer: HR-IVA®
When the gas sample is smaller than 0.01cc, the gas flow is not long enough to scan through the mass range. ORS developed the HR-IVA® with a TOF mass spectrometer. After the formation of ions, they are injected in the Flight Path with the same initial energy. Light ions travel faster, heavy ones travel slower. Ions impact a detector plate whose voltage is monitored. With this analytical technique, the travel time is a function of the square root of mass-to-charge ratio.
The main advantage of this equipment is that it gives at least 100 times more data points than the IVA®. It is therefore possible to acquire a lot of data during the very fast burst of a 0.0001 atm·cc package!