A method for detecting a blockage in a filter mesh of an indoor unit includes: obtaining a first resistance difference value of the filter mesh under a preset air volume value; determining a first external static pressure value during an operation process of the indoor unit; and determining that the filter mesh is blocked based on a numerical relationship between the first external static pressure value, the preset external static pressure value, and the first resistance difference value. The blockage of the filter mesh may be determined in time during the operation process of the air conditioner.

Each time clogging of a filter (5) of an air cleaner is determined on the basis of intake negative pressure of an engine (2), and the air filter (5) is cleaned, an accumulated value of operating time of the engine (2) from previous cleaning until clogging is determined is taken as a cleaning interval (S), and sequentially measured. A plurality of stages are previously set by classifying a minimum value and a maximum value of the cleaning interval (S), and the measured cleaning interval (S) is added to the stage to which the measured cleaning interval (S) is to belong, among the stages. A histogram in which an axis of abscissas is taken as the stage, an axis of ordinates is taken as frequency of the cleaning interval (S) is constructed, and an approximate straight line (L2) illustrated by a solid line is obtained by approximating a characteristic line (L1) of the histogram illustrated by a dotted line to a straight line. A characteristic of the histogram is changed as the deterioration of the air filter (5) progresses, and when a slope of the approximate straight line (L2) based on the characteristic gradually decreases from right-upward slop illustrated by a thin line, exceeds (?Y/?X=0) equivalent to the horizontal, deterioration of the air filter is determined.

Disclosed is a system and a method for testing at least one filtration device. The system comprises a chromatography system (3) comprising at least one pair of inlet and outlet chromatography column connections (7a), 7b for at least one chromatography column, and at least one filtration device housing (21) comprising a filtration device (23) to be tested, whereby each filtration device housing (21) is connected to one of the at least one pair of inlet and outlet chromatography column connections (7a, 7b) instead of a chromatography column in the chromatography system.

Embodiments herein relate to air filtration monitoring systems that can measure air volume and/or air velocity. In an embodiment a monitoring system for industrial dust collectors is included having a pressure sensor and a control circuit, wherein the control circuit can be in signal communication with the pressure sensor. The monitoring system can store a previously measured air volume value and/or air velocity value and can calculate real time air volume values and/or real time air velocity values using data from the pressure sensor and the previously measured air volume value and/or air velocity value. Other embodiments are also included herein.

The present disclosure relates, according to some embodiments, to methods of marker based direct integrity testing of at least one membrane comprising: (a) dosing a feed fluid of a loop with at least one marker comprising at least one challenge particle, the loop comprising: the feed fluid; a pump comprising an outlet stream; a membrane module comprising the at least one membrane and a membrane module outlet stream, wherein the membrane module is in fluid communication with the outlet stream; a marker recycle stream in fluid communication with the membrane module outlet stream and the pump; and a means to measure particle concentrations; (b) circulating the feed fluid through the membrane module at least once to produce a filtrate comprising a filtered at least one marker; (c) measuring a filtrate particle concentration of the filtered at least one filtered marker in the filtrate to produce a filtrate concentration measurement; and (d) calculating a log removal value from the filtrate concentration measurement and the feed concentration measurement; wherein the log removal value is less than about 3 m.

A method for providing an integrity test of a double filter capsule can include providing the double filter capsule in such a way that in a filtration process the medium to be filtered flows in its flow direction from an upstream chamber in the housing through a first filter into an intermediate chamber between the first filter and a second filter and then through the second filter to an outlet. The housing can have an upstream-chamber access point for feeding a test fluid into the upstream chamber and an intermediate-chamber access point for feeding the test fluid into the intermediate chamber. Additional steps can include providing a connecting line between the upstream-chamber access point and the intermediate-chamber access point and determining the state of integrity of the double filter capsule on the basis of at least two test phases.

A carbon dioxide (CO.sub.2) separation membrane plant abnormality detection system includes: an entrance unit through which gas containing CO.sub.2 enters a plant including a CO.sub.2 separation membrane module; a separation membrane module; a permeation unit configured to discharge the gas with the relatively high CO.sub.2 concentration, which is discharged from the separation membrane module, to the outside of the plant; a residue unit configured to discharge the gas with the relatively low CO.sub.2 concentration, which is discharged from the separation membrane module, to the outside of the plant; a measurer configured to measure information; and a controller configured to determine the presence of an abnormality, wherein the controller determines whether the plant is in an abnormal situation.

A system and method for accurately and efficiently testing a HEPA filter in a sterile environment, such as a clean room, by creating a closed-loop system. The system includes a multi-port interface including at least a challenge port and a verification port, each port being in communication with an area upstream from the HEPA filter. Through the challenge port, test substances are introduced to a supply air duct that is in communication with a HEPA filter. Through the verification port, a concentration of the test substances can be measured for comparison with a concentration that passed through the HEPA filter, i.e. downstream from the HEPA filter. As such, test substances can be dispersed throughout the air conditioning system before interacting with the HEPA filter, and accurately measured. The closed loop between the ports provides an accurate measurement of the concentration of test substances to test the HEPA filter.

Acquiring sets of test data on amounts of foreign matter passed through a recirculation sump screen when different amounts of foreign matter are input; forming a passed foreign matter amount approximate line that approximates the amounts of passed foreign matter with respect to the amounts of input foreign matter on the basis of the sets of test data on the amounts of passed foreign matter; forming a passed foreign matter amount envelope tangent to the passed foreign matter amount approximate line; and estimating a total passed foreign matter amount with respect to the amounts of input foreign matter on the basis of the passed foreign matter amount envelope to evaluate the recirculation sump screen are provided.

Methods and systems are provided for determining condition of an air filter coupled to an intake passage of an engine system. In one example, a method may include estimating a resistance of the air filter based on a manifold air charge value. The manifold air charge value may be either a mass air flow or a manifold air pressure.