Difference between revisions of "FAQ AMS Glossary"
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| + | This is a glossary of terms and acronyms typically used by the AMS community. It is a work in progress - so is by no means complete or comprehensive. Please continue to add and edit! | ||
| + | == Hardware and Data Acquisition == | ||
| − | + | * '''AMS''': Aerosol Mass Spectrometer. In our community it always means the Aerodyne AMS, but a few other groups have named other instruments "AMS", which are unrelated to the Aerodyne AMS. | |
| − | + | * '''CRiTTR''': Piece of software to run the pulsers and move the chopper independently of the AMS Data Acquisition software (DAQ) | |
| − | + | * '''DAQ''': Data Acquisition Software | |
| − | + | * '''SP-AMS''': Soot Particle AMS. New instrument developed which combines the SP2 (Single Particle Soot Photometer) particle vaporization and the AMS ionization and mass spectrometry. | |
| − | |||
| − | + | == Analysis Software and Results == | |
| − | + | * '''APES''': Analytic Procedure for Elemental Separation. An Igor tool for performing an elemental analysis (i.e. O/C ratio). In Pika 1.07 most of this code was merged with the pika code, but a version of APES remain as a stand-alone Igor code. | |
| − | Background:In general this term should be avoided as it is too ambiguous. (Background ambient measurement conditions? Background instrumental signal? etc.) The use of 'Closed mass spectra' is encouraged where appropriate. | + | * '''Background:''' In general this term should be avoided as it is too ambiguous. (Background ambient measurement conditions? Background instrumental signal? etc.) The use of 'Closed mass spectra' is encouraged where appropriate. |
| − | Baseline: In a mass spectra, the 'region between the peaks' for an open, closed or difference mass spectra. | + | * '''Baseline''': In a mass spectra, the 'region between the peaks' for an open, closed or difference mass spectra. |
| − | Closed: The mass spectrum taken with the chopper in the 'blocked' position, and typically considered instrument background and gas-phase contribution to AMS signal | + | * '''Closed''': The mass spectrum taken with the chopper in the 'blocked' position, and typically considered instrument background and gas-phase contribution to AMS signal |
| − | + | * '''Diff''': The Difference Spectrum; difference in chopper-open mass spectrum and chopper-closed mass spectrum; typically considered the mass spectrum due to particle signal | |
| − | + | * '''f_x''': the fraction of the total organic signal that is observed at m/z = x. E.g. f_44 is the fraction of the total OA signal at m/z 44. Sometimes also written as 44/Org or 44/OA. | |
| − | + | * '''fragments''': a vaporized molecule is ionized in the AMS to a series of ions, which are then detected by either a quadrupole or time-of-flight mass spectrometer; the resulting ions are referred to as 'fragments' | |
| − | + | * '''Non-refractory (NR) species''': chemical components of aerosol that are volatilized in the AMS, and are observed in the "Difference spectrum". This requires evaporation in a time scale shorter than chopper open/closed movement, whish is typically 3-5 seconds. Examples include the usual AMS species: sulfate, nitrate, ammonium, chloride, and organic (OA). Note that these species can also have some semi-refractory signal, although this is typically a small fraction (5-10% of the NR signal under typical operating conditions). | |
| − | + | * '''Refractory species''': chemical components of aerosol that are not volatile enough to vaporize in the AMS in a time scale of at least a few hours, and thus are never observed by the instrument. Examples include black carbon (see SP2-AMS). | |
| − | + | * '''Semi-refractory(SR) species''': chemical components of aerosol that are relatively less volatile, and only slowly vaporize in the AMS. Functionally, they are observed in both the the Closed and Open signals (time-scale for vaporization is much longer than the time scale of open/closed chopper movement). Examples include some chemical forms of Pb (lead) and possibly NaCl. | |
| − | HR: High Resolution (as opposed to UMR, typically referring to either the High Resolution Time of Flight Aerosol Mass Spectrometer, or to the data derived from that instrument) | + | * HR: High Resolution (as opposed to UMR, typically referring to either the High Resolution Time of Flight Aerosol Mass Spectrometer, or to the data derived from that instrument) |
| − | ipf: Igor Procedure File | + | * ipf: Igor Procedure File |
| − | |||
| − | + | == PMF-Related == | |
| − | + | * '''BBOA''': Biomass Burning Organic Aerosol | |
| − | + | * '''HOA''': Hydrocarbon-like Organic Aerosol | |
| − | + | * Light Scattering: | |
| − | + | * '''LV-OOA''': Low volatility-oxygenated organic aerosol | |
| − | + | * '''OOA''': Oxygenated Organic Aerosol | |
| − | + | * Open: Mass spectra acquired when the chopper is in the 'open' position - both air and aerosols are entering and being detected | |
| − | + | * PET: PMF Evaluation Tool. An interface for examining the results of many PMF analyses. | |
| − | + | * PIKA: Peak Integration by Peak Analysis. This is a somewhat contorted acronym, but this name really indicates "High Resolution Analysis" or HR analysis where individual peaks (C3H6 and C2H2O at ~ m/z 42). | |
| − | + | * PMF: Positive Matrix Factorization | |
| − | + | * Q: This has two uses. Q often refers to a quadropole AMS. But Q and Qexp are terms also used in a PMF analysis. | |
| − | SPARROW: Single PARicle Retrieval Of Waves. The Igor analysis tool for AMS light scattering data. | + | * SPARROW: Single PARicle Retrieval Of Waves. The Igor analysis tool for AMS light scattering data. |
| − | SQUIRREL: SeQUential Igor data RetRiEvaL. The Igor analysis tool for non-Quad AMS data. | + | * SQUIRREL: SeQUential Igor data RetRiEvaL. The Igor analysis tool for non-Quad AMS data. |
| − | SV-OOA: Semi-Volatile Oxidized Organic Aerosol | + | * SV-OOA: Semi-Volatile Oxidized Organic Aerosol |
| − | ToF: Time of Flight mass spectrometer | + | * ToF: Time of Flight mass spectrometer |
| − | UMR: Unit Mass Resolution (as opposed to HR: ie, signal observed at m/z 28 is UMR, whereas HR data typically shows two peaks, one from N2+ and another from CO+) | + | * UMR: Unit Mass Resolution (as opposed to HR: ie, signal observed at m/z 28 is UMR, whereas HR data typically shows two peaks, one from N2+ and another from CO+) |
Revision as of 15:03, 23 February 2010
This is a glossary of terms and acronyms typically used by the AMS community. It is a work in progress - so is by no means complete or comprehensive. Please continue to add and edit!
Hardware and Data Acquisition
- AMS: Aerosol Mass Spectrometer. In our community it always means the Aerodyne AMS, but a few other groups have named other instruments "AMS", which are unrelated to the Aerodyne AMS.
- CRiTTR: Piece of software to run the pulsers and move the chopper independently of the AMS Data Acquisition software (DAQ)
- DAQ: Data Acquisition Software
- SP-AMS: Soot Particle AMS. New instrument developed which combines the SP2 (Single Particle Soot Photometer) particle vaporization and the AMS ionization and mass spectrometry.
Analysis Software and Results
- APES: Analytic Procedure for Elemental Separation. An Igor tool for performing an elemental analysis (i.e. O/C ratio). In Pika 1.07 most of this code was merged with the pika code, but a version of APES remain as a stand-alone Igor code.
- Background: In general this term should be avoided as it is too ambiguous. (Background ambient measurement conditions? Background instrumental signal? etc.) The use of 'Closed mass spectra' is encouraged where appropriate.
- Baseline: In a mass spectra, the 'region between the peaks' for an open, closed or difference mass spectra.
- Closed: The mass spectrum taken with the chopper in the 'blocked' position, and typically considered instrument background and gas-phase contribution to AMS signal
- Diff: The Difference Spectrum; difference in chopper-open mass spectrum and chopper-closed mass spectrum; typically considered the mass spectrum due to particle signal
- f_x: the fraction of the total organic signal that is observed at m/z = x. E.g. f_44 is the fraction of the total OA signal at m/z 44. Sometimes also written as 44/Org or 44/OA.
- fragments: a vaporized molecule is ionized in the AMS to a series of ions, which are then detected by either a quadrupole or time-of-flight mass spectrometer; the resulting ions are referred to as 'fragments'
- Non-refractory (NR) species: chemical components of aerosol that are volatilized in the AMS, and are observed in the "Difference spectrum". This requires evaporation in a time scale shorter than chopper open/closed movement, whish is typically 3-5 seconds. Examples include the usual AMS species: sulfate, nitrate, ammonium, chloride, and organic (OA). Note that these species can also have some semi-refractory signal, although this is typically a small fraction (5-10% of the NR signal under typical operating conditions).
- Refractory species: chemical components of aerosol that are not volatile enough to vaporize in the AMS in a time scale of at least a few hours, and thus are never observed by the instrument. Examples include black carbon (see SP2-AMS).
- Semi-refractory(SR) species: chemical components of aerosol that are relatively less volatile, and only slowly vaporize in the AMS. Functionally, they are observed in both the the Closed and Open signals (time-scale for vaporization is much longer than the time scale of open/closed chopper movement). Examples include some chemical forms of Pb (lead) and possibly NaCl.
- HR: High Resolution (as opposed to UMR, typically referring to either the High Resolution Time of Flight Aerosol Mass Spectrometer, or to the data derived from that instrument)
- ipf: Igor Procedure File
PMF-Related
- BBOA: Biomass Burning Organic Aerosol
- HOA: Hydrocarbon-like Organic Aerosol
- Light Scattering:
- LV-OOA: Low volatility-oxygenated organic aerosol
- OOA: Oxygenated Organic Aerosol
- Open: Mass spectra acquired when the chopper is in the 'open' position - both air and aerosols are entering and being detected
- PET: PMF Evaluation Tool. An interface for examining the results of many PMF analyses.
- PIKA: Peak Integration by Peak Analysis. This is a somewhat contorted acronym, but this name really indicates "High Resolution Analysis" or HR analysis where individual peaks (C3H6 and C2H2O at ~ m/z 42).
- PMF: Positive Matrix Factorization
- Q: This has two uses. Q often refers to a quadropole AMS. But Q and Qexp are terms also used in a PMF analysis.
- SPARROW: Single PARicle Retrieval Of Waves. The Igor analysis tool for AMS light scattering data.
- SQUIRREL: SeQUential Igor data RetRiEvaL. The Igor analysis tool for non-Quad AMS data.
- SV-OOA: Semi-Volatile Oxidized Organic Aerosol
- ToF: Time of Flight mass spectrometer
- UMR: Unit Mass Resolution (as opposed to HR: ie, signal observed at m/z 28 is UMR, whereas HR data typically shows two peaks, one from N2+ and another from CO+)
