Abstract: A high-flow rate, low-noise, gas sampling apparatus for collecting particulate such as biological, chemical, and radioactive material from a gas on a collector such as an impaction collector includes a housing having an inlet and an outlet and a fan disposed within the housing for drawing the gas into the inlet, past the collector for sampling, and exhausting the gas through the outlet. The fan is operable to produce a flow of gas through the housing of greater than about 50 liters per minute with a noise level emitted from the apparatus being less than about 60 decibels. The apparatus may be configured as a compact, unobtrusive, portable, lightweight apparatus for use in various indoor or outdoor locations. The apparatus may also include a sensor for the detection of radioactive material collected on the collector, a processor for monitoring the sampling, and the apparatus may be linked to a communications network such as the Internet. Methods for collecting particulate from a gas are also enclosed.

Abstract: A sampling cartridge for a gas sampling apparatus includes a shell having a cylindrical wall and a sampling window extending through the wall. A pair of spools are coaxially and internally positioned within the shell. The spools are independently rotatable relative to the shell. A first spool may include multiple interval sample collectors while the second spool includes a duration sample collector. Each spool also has a window closing surface which is positioned adjacent the window whenever an access door of the gas sampling apparatus is opened. The sampling cartridge may also include a fully encapsulated section of sample collector material as a negative control, and an integral RF tag for storing chain of custody information including personal identification information of a cartridge replenisher.

Abstract: A sampling cartridge for a gas sampling apparatus includes a shell having a cylindrical wall and a sampling window extending through the wall. A pair of spools are coaxially and internally positioned within the shell. The spools are independently rotatable relative to the shell. A first spool may include multiple interval sample collectors while the second spool includes a duration sample collector. Each spool also has a window closing surface which is positioned adjacent the window whenever an access door of the gas sampling apparatus is opened. The sampling cartridge may also include a fully encapsulated section of sample collector material as a negative control, and an integral RF tag for storing chain of custody information including personal identification information of a cartridge replenisher.

Abstract: A sampling cartridge for a gas sampling apparatus includes a shell having a cylindrical wall and a sampling window extending through the wall. A pair of spools are coaxially and internally positioned within the shell. The spools are independently rotatable relative to the shell. A first spool may include multiple interval sample collectors while the second spool includes a duration sample collector. Each spool also has a window closing surface which is positioned adjacent the window whenever an access door of the gas sampling apparatus is opened. The sampling cartridge may also include a fully encapsulated section of sample collector material as a negative control, and an integral RF tag for storing chain of custody information including personal identification information of a cartridge replenisher.

Abstract: A sampling cartridge for a gas sampling apparatus includes a shell having a cylindrical wall and a sampling window extending through the wall. A pair of spools are coaxially and internally positioned within the shell. The spools are independently rotatable relative to the shell. A first spool may include multiple interval sample collectors while the second spool includes a duration sample collector. Each spool also has a window closing surface which is positioned adjacent the window whenever an access door of the gas sampling apparatus is opened. The sampling cartridge may also include a fully encapsulated section of sample collector material as a negative control, and an integral RF tag for storing chain of custody information including personal identification information of a cartridge replenisher.

Abstract: A gas particle partitioner (GPP) removes particles from an aerosol with high efficiency and with no or minimum changes to the thermodynamic conditions and chemical composition of the gas phase of the aerosol. A permeable grid electrode surrounds a corona wire and separates an interior corona discharge area from an exterior aerosol charging zone. A particle free fluid washes the corona discharge area to minimize any transport of gas components produced by corona discharge to the aerosol. The charged particles in the aerosol are deflected by an electric field in a fractionator to selectively produce a particle free sample stream, which is then separated by a flow splitter from the aerosol.

Abstract: A sampling cartridge for a gas sampling apparatus includes a shell having a cylindrical wall and a sampling window extending through the wall. A pair of spools are coaxially and internally positioned within the shell. The spools are independently rotatable relative to the shell. A first spool may include multiple interval sample collectors while the second spool includes a duration sample collector. Each spool also has a window closing surface which is positioned adjacent the window whenever an access door of the gas sampling apparatus is opened. The sampling cartridge may also include a fully encapsulated section of sample collector material as a negative control, and an integral RF tag for storing chain of custody information including personal identification information of a cartridge replenisher.

Abstract: A high-flow rate, low-noise, gas sampling apparatus for collecting particulate such as biological, chemical, and radioactive material from a gas on a collector such as an impaction collector includes a housing having an inlet and an outlet and a fan disposed within the housing for drawing the gas into the inlet, past the collector for sampling, and exhausting the gas through the outlet. The fan is operable to produce a flow of gas through the housing of greater than about 50 liters per minute with a noise level emitted from the apparatus being less than about 60 decibels. The apparatus may be configured as a compact, unobtrusive, portable, lightweight apparatus for use in various indoor or outdoor locations. The apparatus may also include a sensor for the detection of radioactive material collected on the collector, a processor for monitoring the sampling, and the apparatus may be linked to a communications network such as the Internet. Methods for collecting particulate from a gas are also enclosed.

Abstract: The mass of particulate matter in a particle laden gas stream is measured using a single mass detector. The particle laden gas stream and a substantially identical but particle-free gas stream alternately engage the mass detector during successive measurement time periods. A difference between a reading provided by the mass detector for a current measurement time period and a reading provided by the mass detector for a consecutive measurement time period is determined. This difference intrinsically corrects for volatilization losses occurring during the current measurement time period. A measure of the mass or concentration of particulate matter in the particulate laden gas is determined from this difference.

Abstract: A gas particle partitioner (GPP) removes particles from an aerosol with high efficiency and with no or minimum changes to the thermodynamic conditions and chemical composition of the gas phase of the aerosol. A permeable grid electrode surrounds a corona wire and separates an interior corona discharge area from an exterior aerosol charging zone. A particle free fluid washes the corona discharge area to minimize any transport of gas components produced by corona discharge to the aerosol. The charged particles in the aerosol are deflected by an electric field in the fractionator to selectively produce a particle free sample stream, which is then separated by a flow splitter from the aerosol.

Abstract: The mass of particulate matter in a particle laden gas stream is measured using a single mass detector. Switching means causes the particle laden gas stream and a substantially identical but particle-free gas stream to alternately engage the mass detector during successive measurement time periods. A difference between a reading provided by the mass detector for a current measurement time period and a reading provided by the mass detector for a consecutive measurement time period is determined. This difference intrinsically corrects for volatilization losses occurring during the current measurement time period. A measure of the mass or concentration of particulate matter in the particulate laden gas stream is determined from this difference.

Abstract: The mass of particulate of an effluent gas flowing in a stack is measured with a mass measurement assembly in which sampling is isokinetically controlled by determining in real-time the molecular weight of the effluent gas, and in particular, determining the moisture content of water vapor in the effluent gas. Readings from a pair of flow sensors connected in series and separated by a dryer are compared to provide a real-time moisture measurement of the effluent gas. The moisture measurement is used to determine a total molecular weight of the effluent gas in real-time and the velocity of the effluent gas in real-time for isokinetic sampling during measurement of the mass of particulate flowing in the effluent gas.

Abstract: A conditioner, system and methods for conditioning a sample gas stream for particulate matter measurement purposes employs a sample gas stream conduit having an: inlet and an outlet and a sample gas stream conditioner in communication with the sample gas stream conduit. The sample gas stream conditioner includes a moisture control system, wherein the moisture control system regulates a humidity level of the sample gas stream flowing through the sample gas stream conduit to maintain a selectable humidity level at the particulate matter collector. A particulate matter measurement instrument is in communication with the sample gas stream outlet and measures the particulate matter in the sample gas stream. Alternative methods for regulating the humidity level at a particulate matter collector in the measurement instrument are also disclosed.

Abstract: The mass of particulate matter in a particle laden gas stream is measured using a first mass detector and a second mass detector. Switching means causes the particle laden gas stream and a substantially identical but particle-free gas stream to alternately engage the first mass detector and the second mass detector respectively during successive measurement time periods. A difference between a reading provided by the first mass detector and a reading provided by the second mass detector for each of the successive measurement time periods is determined. This difference intrinsically corrects for volatilization losses occurring during the measurement time periods. A measure of the mass or concentration of particulate matter in the particulate laden gas stream is determined from this difference.

Abstract: A conditioner, system and methods for conditioning a sample gas stream for particulate matter measurement purposes employs a sample gas stream conduit having an inlet and an outlet and a sample gas stream conditioner in communication with the sample gas stream conduit. The sample gas stream conditioner includes a moisture control system, wherein the moisture control system regulates a humidity level of the sample gas stream flowing through the sample gas stream conduit to maintain a selectable humidity level at the particulate matter collector. A particulate matter measurement instrument is in communication with the sample gas stream outlet and measures the particulate matter in the sample gas stream. Alternative methods for regulating the humidity level at a particulate matter collector in the measurement instrument are also disclosed.

Abstract: An air sampler having an automatic sample collector changer includes a supply magazine for holding a supply of fresh sample collectors and a receiving magazine for receiving and storing used collectors located aside a sampling station. A transfer mechanism transfers a fresh collector from the supply magazine to the sampling station and a used collector from the sampling station to an entrance of the receiving magazine. An automatic closer or plunger closes the entrance of the receiving magazine following transfer thereto of a used collector. The supply magazine can include an actuator for displacing a stack of sample collectors contained in said magazine. This stack may include interspersed air impervious covers. The transfer mechanism can transfer both a sample collector and a cover to the receiving magazine. Interspersing of covers with used sample collectors in the receiving magazine reduces volitization losses. For the same purpose, the temperature of the receiving magazine can be controlled.

Abstract: An air sampler having an automatic sample collector changer includes a supply magazine for holding a supply of fresh sample collectors and a receiving magazine for receiving and storing used collectors located aside a sampling station. A transfer mechanism transfers a fresh collector from the supply magazine to the sampling station and a used collector from the sampling station to an entrance of the receiving magazine. An automatic closer or plunger closes the entrance of the receiving magazine following transfer thereto of a used collector. The supply magazine can include an actuator for displacing a stack of sample collectors contained in said magazine. This stack may include interspersed air impervious covers. The transfer mechanism can transfer both a sample collector and a cover to the receiving magazine. Interspersing of covers with used sample collectors in the receiving magazine reduces volitization losses. For the same purpose, the temperature of the receiving magazine can be controlled.

Abstract: The mass of particulate of an effluent gas flowing in a stack is directly measured with a mass measurement assembly supported within the stack. The mass measurement assembly preferably includes an inertial mass measurement transducer which provides near real-time mass readings. The mass measurement assembly also includes a particulate collector which can be equilibrated in situ. A pressure transducer measures a pressure differential across the equilibrated collector prior to sampling, to determine a pressure coefficient of frequency in a calibration operation. The pressure transducer also measures a pressure differential across the collector during sampling which measurement is used along with the pressure coefficient of frequency to derive an adjusted mass reading, corrected to compensate for pressure changes.

Abstract: The mass of particulate of an effluent gas flowing in a stack is directly measured with a mass measurement assembly supported within the stack. The mass measurement assembly preferably includes an inertial mass measurement transducer which provides near real-time mass readings. The mass measurement assembly also includes a particulate collector which can be equilibrated in situ. A conditioned gas line supplies clean, dry, heated conditioned gas to the collector for equilibration. The flow rate of the conditioned gas prevents effluent gas from reaching the collector during equilibration. The collector can be equilibrated in the stack before and after sampling and between intermittent sampling periods.

Abstract: A carrier supporting multiple filters is inserted jointly with the filters into an air sampler. The carrier includes an indexing structure to ensure correct positioning within the air sampler. A memory device physically associated with the carrier stores sample collection data provided by the air sampler. The stored data can be read by a read/write station at a lab, and transmitted to a processor. The processor also receives a weight reading from a communicating balance for each collected sample, and calculates therefrom mass concentration for each sample.