A performance indication device for a filter is provided. The performance indication device includes a water metering device to convert the energy of water flowing through the filter into mechanical rotation of a drive gear. A gear reduction assembly operably couples the drive gear to a valve gear and reduces the rotational speed of the valve gear relative to the drive gear. A flow controlling device is operably coupled to the valve gear and is configured to reduce or terminate the flow of water through the performance indication device and the filter when a target flow capacity is reached. The performance indication device thus provides an accurate indication to the user as to when the filter capacity has been expended without the need for a complex control system or communication link or any modification of the appliance in which the filter is installed.

A correcting system includes an acquisition unit, a storage unit, and a correction unit. The acquisition unit acquires information indicating first capture efficiency of a filter for first microscopic particles. The storage unit stores correction data to correct the first capture efficiency to second capture efficiency of the filter for second microscopic particles. The correction unit corrects the first capture efficiency acquired by the acquisition unit to the second capture efficiency based on the correction data.

Methods and systems for determining the integrity of a filter device are provided.

An apparatus includes (i) a test chamber having an inlet and an outlet; (ii) an introduction system configured to introduce a test pollutant into the test chamber such that the test pollutant is entrained in air flowing from the inlet to the outlet; (iii) a support configured to retain the test article, wherein the support defines a passageway downstream of a location of the test article such that air flowing from the inlet to the outlet passes through the filter medium prior to entering the passageway; (iv) an air flow apparatus configured to draw air from within the test chamber through the passageway and the outlet; and (v) a respiratory conditions simulation system configured to simulate an aspect of respiration, an external environment simulation system configured to simulate an aspect of an external environment, or both the respiratory conditions simulation system and the external environment simulation system.

Systems and methods for operating an engine that includes an exhaust system with a differential pressure sensor are described. In one example, output of the differential pressure sensor is compared to output of a barometric pressure sensor to determine whether or not the barometric pressure sensor is degraded. The output of the differential pressure sensor may be monitored while the engine is rotated without being fueled.

Defect detection systems include at least one nozzle for delivering a CO.sub.2 particulate fluid to an inlet end of a plugged honeycomb body. Defects in the honeycomb, if any, are determined by monitoring CO.sub.2 particulate flow at the outlet end of the honeycomb body. Methods for detecting defects in plugged honeycomb bodies are also disclosed.

An integrity testing method for a porous medium in a housing having an interior separated by the medium into upstream and downstream portions, an inlet and an outlet communicating, respectively, with the upstream and downstream portions, the outlet connected to a closeable conduit, comprises filling the downstream portion and conduit with liquid, draining the upstream portion and filling it with gas while retaining liquid in the downstream portion, connecting a gas-filled testing volume to the downstream portion, maintaining gas pressure of a predetermined testing differential pressure in the upstream portion, the differential pressure being lower than a predefined bubble point of the medium, determining the pressure in the testing volume, the testing volume selected such that, when a medium is tested having a bubble point corresponding to the predefined bubble point, a pressure increase within the testing volume of about 100 mbar or more is obtained within 10 minutes.

One embodiment provides a system, including: at least two water analyzers, wherein at least one of the at least two water analyzers is positioned upstream of a purification apparatus and wherein at least another of the at least two water analyzers is positioned downstream of the purification apparatus; at least one processor; and a memory device that stores instructions executable by the processor to: receive water analysis data from the at least two water analyzers, wherein the water analysis data comprises information related to membrane integrity; identify an algorithm for calculating membrane integrity based upon received data corresponding to system attributes; and calculate, using the identified algorithm, the membrane integrity based upon the received water analysis data. Other aspects are described and claimed.

Apparatus and methods are disclosed which are capable of being used to determine filtration efficiency of a filter body even in a clean state. Methods of determining a filtration efficiency of a filter including forcing an inlet flow comprised of a gas (such as air) flow into the inlet end of the filter at a set flow rate, introducing particles such as smoke particles into the inlet flow, and optically counting the number of particles entering and exiting the filter during a sampling event, such as with diffraction based optical particle counters positioned upstream and downstream of the filter. Preferably the gas flow is a soot-free flow stream which does not load the honeycomb filter body with contaminants that need to be removed or burned out. The filter body can thus remain in an essentially clean state even after testing its filtration efficiency.

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.