Time-of-Flight Mass Spectrometer Instrument
AE Receives Equipment Donation to Assist in Indoor Environment Center Research
United Technologies Research Center, the central research organization for United Technologies Corporation (Carrier HVAC, Pratt & Whitney Aircraft Engines, Sikorsky Helicopter, Hamilton-Sundstrand Controls, UTC Power International Fuel Cells, Otis Elevator, CHUBB Fire and Safety Security) has donated a Comstock Corporation designed-and-built Reflectron Time-of-Flight (TOF) Mass Spectrometer to the Indoor Environment Center of the Department of Architectural Engineering. Comstock Corporation is recognized as a world leader in TOF instrumentation. 
In principle, the instrument enables the measurement of the chemical composition of a gaseous input stream at part per billion (ppb) levels and below, depending on the particular target compound. Since the instrument scans a complete “ion mass spectra” in milliseconds, the device can be used to follow rapidly changing concentrations in an input stream, or the real-time decrease in a contaminant once a filter or contaminant control device has been activated in the stream. With appropriate accessories the instrument can also be utilized to determine the chemical composition of micron-sized aerosols introduced into the device at similarly low concentrations. TOF instruments are used routinely to monitor the chemical composition of artificial air administered to hospital patients, as well as anesthetic levels. They are also used to monitor the chemical composition of suspended particulate matter in urban
areas on a daily basis.
Measurement of indoor contaminants in the low part per million (ppm) and ppb concentration ranges is necessary, since these are the concentration levels commonly found in indoor environments. Although contaminant concentrations are generally low at any one time in building air supplies, long inhalation exposure times result from the fact that most people spend greater than 90 percent of their time indoors, resulting in significant integrated acquired contaminant dosages. The epidemic increases in allergic sensitization and the subsequent development of asthma are epidemiologically correlated with exposures to low levels of indoor contaminants such as formaldehyde and aerosolized proteins from dust mites, cats and dogs.
In the long term, advanced sensor and air purification technologies are being developed to eliminate low level contaminants, while simultaneously using less overall energy associated with ventilation and air-conditioning, relative to conventional air supply systems - the so-called IAQ approach to ASHRAE 62 standards. The developing demand control ventilation and/or active air treatment approaches will be based on monitored levels of air contaminants: chemical vapors, allergens and microbes. Air treatment technology will be activated only when needed, analogous to demand control ventilation based on CO2 monitoring. Continual operation of advanced air filtration and purification technologies is too energy intensive, given the continually increasing costs of energy. Conventional IAQ needs are mirrored in the building chemical and biological security issues raised by Homeland Security concerns, the so-called “extreme IAQ” cases, the application sector where most of the advanced sensor technology is being developed.
To develop and verify these emerging, active IAQ approaches, one needs instrumentation capable of identifying a broad range of potential contaminants at quantitative levels in the concentration ranges indicated above. And should an air purification technology be developed for a specific type of contaminant, such as ultra-violet light deactivation microbe pathogens, it is important to document if any decontamination by-products result from the air treatment, such as endotoxin fragments from gram-negative bacteria, and, again, at the ppb or low ppm levels.
The Reflectron TOF instrument enables researchers in the Indoor Environment Center to develop and investigate advanced IAQ sensor and air treatment technologies for a broad range of potential contaminants and contaminant concentrations.