A method of integrity testing a porous material is disclosed, providing a porous material suitable for filtration to be tested, said porous material having a first surface and a second surface; wetting said porous material with a wetting liquid; providing a gas stream comprising at least first and second gases humidified with said wetting liquid below the saturation vapor pressure of said wetting liquid and wherein said humidified gas stream has a humidity of 50-99%; introducing said gas stream to said first surface of said porous material; causing said first and second gases to flow through said porous material; measuring the concentration of at least one of said first and second gases in the permeate stream exiting said second surface of said porous material; and comparing the measured concentration to a predetermined concentration.

An aerosol distributor and an arrangement for filter leakage detection in a gas filtration system comprising such aerosol distributor, the aerosol distributor being configured to be positioned in a gas stream upstream of the filter, said aerosol distributor comprising: a housing comprising a primary chamber in fluid connection with two or more secondary chambers; the housing having an inlet for admitting a test aerosol from an aerosol source into the primary chamber and passages for releasing the test aerosol from the primary chamber into each of the secondary chambers; said secondary chambers being elongated and provided with a plurality of outlet holes along the length thereof for releasing the test aerosol from the secondary chambers into a gas stream surrounding the aerosol distributor; characterized in that the dimensions of the inlet, the primary chamber, the passages, the secondary chambers and the outlet holes are selected such that during operation, the pressure of the test aerosol in the primary chamber will be higher than the pressure of the test aerosol in the secondary chambers.

Treatment methods for reduction of (1.fwdarw.3)-β-D-glucan leachables from cellulose-containing filter materials are described.

A method and apparatus for filter testing for use within an air handling system. The air handling system may include one or more scan assemblies. The scan assembly may include a track system using one or more magnetic arrays.

A method for evaluating an air purification system. The method includes generating, with an air flow generator, a flow of air through a test filter so that an upstream air flow exists an upstream side of the test filter and a downstream air flow exists on a downstream side of the test filter. A multiple contaminant mixture is injected, with a fluid injector, into the upstream air flow. Downstream concentrations for each contaminant of the multiple contaminant mixture in the downstream air flow are measured with a contaminant measurement device. Test filter breakthrough curves for each contaminant of the multiple contaminant mixture in the downstream air flow are generated based on the downstream concentrations for each contaminant of the multiple contaminant mixture.

A system can include a filter assembly with a filter and a substance in the filter assembly, and at least one optical computing device having an integrated computational element which receives electromagnetic radiation from the substance. A method can include receiving electromagnetic radiation from a substance in a filter assembly, the electromagnetic radiation from the substance being received by at least one optical computing device having an integrated computational element, and the receiving being performed while a filter is positioned in the filter assembly. A detector may receive electromagnetic radiation from the integrated computational element and produce an output correlated to a characteristic of the substance. A mitigation technique may be selected, based on the detector output.

A vacuum cleaner that includes a suction source configured to generate a suction airflow, a dirt collector in fluid communication with the suction source and configured to separate debris from the suction airflow and the dirt collector is configured to store the debris separated from the suction airflow. The vacuum further includes an infrared sensor operable to output a signal corresponding to a distance to an amount of debris stored in the dirt collector, a controller that receives the signal, and the controller is operable to determine a fill level stored in the dirt collector based on the signal. A visual display displays the fill level stored in the dirt collector.

Treatment methods for reduction of (1.fwdarw.3)-β-D-glucan leachables from cellulose-containing filter materials are described.

A vacuum cleaner that includes a suction source configured to generate a suction airflow, a dirt collector in fluid communication with the suction source and configured to separate debris from the suction airflow and the dirt collector is configured to store the debris separated from the suction airflow. The vacuum further includes an infrared sensor operable to output a signal corresponding to a distance to an amount of debris stored in the dirt collector, a controller that receives the signal, and the controller is operable to determine a fill level stored in the dirt collector based on the signal. A visual display displays the fill level stored in the dirt collector.

A particulate filter having a porous ceramic honeycomb structure with a first end, a second end, and a plurality of walls having wall surfaces defining a plurality of inner channels. Filtration material deposits are disposed on one or more of the wall surfaces of the honeycomb body. The highly porous deposits provide durable high clean filtration efficiency with small impact on pressure drop through the filter.