DE102017130978B3 - System for checking aerosol and flow meters - Google Patents

Abstract

A system (1) for checking aerosol and / or flow measuring devices in a device (4) which can be connected to the system makes it possible to switch between different test operating modes. For this purpose, a switching device (12) is provided, which makes it possible to switch over a gas flow in different ways depending on a desired operating mode, namely in an aerosol validation mode to a reference particle measuring device (13), or in a flow validation mode to a valve unit (16 ) with the reference gas flow measuring device (17). In the aerosol validation mode, at least a portion of the gas flow generated in this mode is passed through the reference particle measuring device (13) while another portion of the gas flow is directed to the device under test (4). In the flow validation mode, at least a portion of the gas flow generated in this mode is routed through the reference gas flow meter (17) and through a component of the device under test.

Description

The invention relates to a system for checking aerosol and / or flow meters.

For emission monitoring of engines and vehicles, it is a legal requirement that the exhaust gases on a test bench or even under real conditions, e.g. on the road, and to investigate their composition in detail. Here, in addition to a variety of pollutant levels especially particulate matter of particular interest. The fine dust particles, for example, nanoparticles, can penetrate deeply into the lungs via the respiration and lead to considerable health impairments. In addition to the particles emitted by engines, particle emissions from other components, such as brake and tire abrasion, can be regulated in a similar manner in the future.

For detecting the particles, corresponding particle measuring devices are known, which are used in test stands or measuring systems equipped therefor. Not least due to legal regulations, particle measuring devices must be regularly maintained, checked and calibrated in order to ensure the required accuracy of measurements on a permanent basis. Examples of such legal regulations are, for example, UNECE Regulation No. 83, Rev. 5, Series 05 or UNECE Regulation No. 49, Rev. 4, Series 05 or the Global Technical Regulation (GTR) No. 15 etc. These regulations require eg a regular review of the systems every 12 months.

Verification of a meter may include validation and / or calibration of the meter. During validation, there is usually only a check to see if the meter still measures with sufficient accuracy within specified limits. Calibration also makes it possible to readjust the device.

An international standard for the calibration of condensation nucleus counts is, for example, the one published in March 2015 ISO 27891 ,

For the calibration of particle measuring devices, it is known to provide a particle generator which generates particles in a mass flow and transfers them to a carrier medium (air, nitrogen, etc.). This so-called "aerosol" is measured in parallel with respect to the particle characteristic to be tested (particle concentration, particle number, particle mass, opacity, etc.) by a reference meter and also supplied to the device to be validated or calibrated. By comparing the measurement results of the reference meter and the device to be checked, the device to be checked can be readjusted.

This process is complex and requires respective conversion measures. For example, must be used for every check, e.g. Validation or calibration, appropriate connections between the reference meter and the device to be tested are created or even during the validation or calibration measure between different inputs are transferred.

From the US 2007/0043976 A1 For example, a system for continuously checking flowmeters with a reference gas flow meter is known.

The invention has for its object to provide a system for checking aerosol and / or flow meters, which allows in a particularly simple and compact way for a user verification of the devices.

The object is achieved by a system having the features of claim 1. Advantageous embodiments can be found in the dependent claims.

• - in einer Aerosolvalidierungs-Betriebsart von einer Partikelquelle zu der Referenz-Partikelmesseinrichtung, oder
• - in einer Flussvalidierungs-Betriebsart zu oder von einer Ventileinheit mit der Referenz-Gasflussmesseinrichtung,

wobei in der Aerosolvalidierungs-Betriebsart wenigstens ein Teil des in dieser Betriebsart erzeugten partikelführenden Gasflusses durch die Referenz-Partikelmesseinrichtung durchgeführt wird und ein anderer Teil des Gasflusses zu dem zu testenden Gerät geführt wird, und wobei in der Flussvalidierungs-Betriebsart wenigstens ein Teil des in dieser Betriebsart erzeugten partikelfreien Gasflusses seriell durch die Referenz-Gasflussmesseinrichtung und von bzw. zu dem an der Anschlusseinrichtung anschließbaren zu testenden Gerät geführt wird.The invention relates to a system for testing aerosol and / or flow measuring devices in a device to be tested, which is to be tested, with a reference particle measuring device, a reference gas flow measuring device, a connection device for connecting a device to be tested, and with a Switching device for switching a gas flow depending on a desired mode in different ways, namely

• in an aerosol validation mode of operation from a particle source to the reference particle measuring device, or
• in a flow validation mode to or from a valve unit with the reference gas flow meter,

wherein in the aerosol validation mode, at least a portion of the particulate gas flow generated in this mode is performed by the reference particulate meter and another portion of the gas flow is directed to the device under test, and wherein in the flow validation mode, at least a portion of the therein Operating mode generated particle-free gas flow is guided serially by the reference gas flow measuring device and from or to the connectable to the connection device to be tested device.

The system thus provides uniform, ie in a compact and possibly independent unit, the Possibility of two different validation modes available, namely aerosol validation and flow validation. With the two validation operating modes, the corresponding aerosol or flow measuring device can be validated and calibrated on a case-by-case basis in the device that can be connected to the system, for example a test or test bench device or the like. In the aerosol validation mode, the system provides a corresponding (defined) conditioned aerosol precisely metered by the reference particle meter. In the flow validation mode, the system provides a precisely defined gas flow that is measured in the system by the reference gas flow meter.

Since the overall accuracy of the system under test depends on the one hand by the interaction of a plurality of internal gas flow measuring devices and on the other of the characteristic of a plurality of particle-guiding components and the internal particle sensor, the combination of the two modes now from a detailed and easy way, a detailed review All relevant parameters are made or a simple identification and localization of errors.

The system will also be referred to as a "test system" below.

The reference gas flow measuring device may in particular be a reference mass flow measuring device. The mass flow measuring devices described below can thus also be understood as gas flow measuring devices.

For aerosol validation, an aerosol with known particle concentration, particle size (optional) and pressure is provided in the aerosol validation mode. The gas or mass flow (mass, volume) can remain unknown and does not have to be measured in this case. The aerosol gas flow or particle flow is split and guided parallel to the reference particle measuring device and the device under test or to the device to be tested (or to a component) present in the device to be tested.

In the flow validation mode, the gas flow is serially routed through the reference gas flow meter and a gas flow meter in the device under test.

The flow direction of the gas flow can be suitably selected and set in the flow validation mode. Thus, the gas flow can first flow through the test system with the respectively selected reference gas flow measuring devices and then through the device to be tested or the component to be tested arranged there. Likewise, conversely, the gas flow can first flow through the device under test and then be led to the test system and the reference gas flow measuring devices.

Despite the realization of both flow directions (into the device to be tested), e.g. by means of a solenoid valve unit, the flow direction can be kept the same by a directional reference mass flow device.

For the flow validation, a defined mass flow is generated, which flows between the system and the device under test, whereby the direction of flow (from the test system to the device or vice versa) can be selected according to the circumstances or the test method.

The operation of the test system as well as the switching between the operating modes as well as the execution of various tests within one operating mode can take place automatically. In this way, particle measurement systems can be easily and conveniently validated and calibrated at the desired time intervals. As desired, any tests possible by the system, or even a selection of tests, can be automated and without further user interaction (e.g., rebuilding operations). For this purpose, the device to be tested by the system can be automated (remote) to control in conjunction with the pneumatic realization of the system (eg, the later-discussed solenoid valve unit and the ball valve unit) and the device under test all gas paths to be tested to realize.

The device under test has e.g. the particle measuring systems or flow measuring systems to be tested in test facilities or test stands and can be connected in a simple manner to the connection device. The connection device can thus provide the necessary or sensible connection possibilities in order to be able to connect the device to be tested to the test system and to realize the desired gas paths to the measuring devices arranged in the device to be tested. Thereby, e.g. Hose couplings, connectors, screw connections, bayonet connections may be present. In addition, corresponding line paths are provided to perform the desired gas flows (e.g., air, aerosol, etc.).

In one embodiment, the size-dependent efficiency of the entire device under test as well as its individual (sensor) components can be automatically detected.

A particle source may be provided in the test system for providing a gas flow particle flow for the aerosol validation mode of operation. The particle source includes, inter alia, a particle generator and a particle conditioning, eg in the form of eg dilution and particle classification. The particle source thus provides the aerosol to the test system in the desired manner, that is to say conditioned in particular with regard to the desired parameters.

Accordingly, the particle source can be used in the aerosol validation mode to generate a particle-carrying gas flow. In the flow validation mode, however, the particle source or its operation is not required because only a particle-free gas flow is needed there.

A particle source is known in particular for producing an aerosol per se and can be constructed in a suitable manner and have corresponding components. It may comprise a per se known particle generator for generating particles. The particles may be passed into a gas stream to form the aerosol. The particle generator can thus generate an aerosol which can then be diluted with dilution air in a dilution system. The dilution can be carried out in one or more stages.

Optionally, a classifying device can also be provided in the particle source which classifies the particles in the aerosol stream upstream, downstream or even between the individual dilution stages.

The correspondingly conditioned aerosol can be divided equally or proportionally in the aerosol validation mode, but in any case homogeneously (equivalent concentrations), namely into a flow to the reference particle measuring device and into another flow to a particle measuring system provided in the device to be tested, that is to be checked.

The switching device decisively influences whether the aerosol validation mode or the flow validation mode is performed and which gas flows or gas paths are respectively formed. For this purpose, in a variant, the switching device having a ball valve switching device. For realizing the flow validation and its multiplicity of gas paths and flow directions, a solenoid valve unit which is in communication with the switching device can be provided.

The supply of the aerosol to the device to be tested can be effected in particular by means of a ball valve unit serving as a switching device, with which the aerosol stream can be supplied to suitable points of the particle measuring system to be checked or calibrated in the aerosol validation mode. In particular, the aerosol flow should thereby be conducted with low loss to the corresponding connection of the device to be tested.

In the flow validation mode effected by the switching means (possibly in conjunction with the solenoid valve unit), a gas flow may be generated which may then be used to direct flow in the particle meter (in the device under test) or flow component in the particle meter. The individual flows or also the total flow can be conditioned in a similar manner as described above. The gas flow is possible in many different ways.

In particular, the device to be tested may be connected to a solenoid valve unit, which in turn determines how and to which component the respective gas flow is directed.

Suitable gas flow measuring devices may be suitable devices, e.g. Mass flow meter (MFM) or volume flow meter.

Individual flows in the particulate meter under test may be calibrated against the reference gas flow meter, which in turn may comprise, for example, a single or two or more intercalated reference gas flow meters. By intercalibration of the two or more reference gas flow meters, it is also possible to compensate for deviations within the reference devices. For this purpose, the solenoid valve unit is in turn designed to allow a serial connection of the reference gas flow meters. Accordingly, the reference gas flow meters can be intercalibrated by means of the solenoid valve realized serial circuit (self-validation). With appropriate design of the switching units and components in the test system itself can be checked with the reference mass flow device (self-validation).

The system represents a complete unit that is able to carry out both flow validation and aerosol validation without any further modifications by the user. In flow validation, all flow-influencing flow elements in the device being tested can be validated against one or more reference flow meters (eg MFM - Mass Flow Meter).

In the case of aerosol validation, the device to be tested, or an internal particle-carrying component or particle sensor component, is compared using a model aerosol relative to the reference particle measuring device (for example a reference particle counting instrument, for example CPC - Condensation Particle Counter).

Validation operations can be performed sequentially, automated, and in any combination of the components involved without removal or modification of components from the device being tested. There is no need for conversion or reloading, for example of pneumatic connections, between the validation system and the device under test. Thus, a conversion during the various test sequences can be avoided. The variety of necessary for this configuration of gas and Aerosolwegen is given by the design of Kugelventileinheit- (multiple ball valves), the solenoid valve unit (variety of directional control valves). Under certain circumstances, switching devices in the system under test may also be used and controlled.

The switching means may comprise a valve means, in particular a ball valve switching means, e.g. a ball valve unit, and a controller for automatically controlling the various modes and switching between the two modes. It is possible, in addition to the two validation modes (flow validation, aerosol validation) to provide other modes, such as a particle-free operation and in particular a working operation in which the device under test is in the normal working mode. Thus, the device under test can be operated smoothly in normal working mode, if the connections remain to the verification system.

The connection device can have a plurality of lines to which the device to be tested can be connected. In addition to the inputs and outputs provided for operation, additional connections can be realized on the device under test in order to realize (in conjunction with the switching devices and switching devices in the device under test) targeted flow paths to individual internal components of the device under test , In this case, it is of particular interest that the device to be tested is only connected once completely to the calibration and validation system via the connection device and thereafter all validation operating modes can be carried out automatically without the need for further conversion or connection measures.

The particle generator is known per se and serves to generate particles in a polydisperse aerosol with a certain particle size distribution.

The dilution system can have a first dilution stage and a second dilution stage (or else further dilution stages), which optionally permit a concentration adjustment and / or a flux increase, depending on the equipment.

To provide a vacuum for the dilution stages and to convey the aerosol and the dilution air, a rotary vane pump may be provided downstream of the dilution system.

In the first dilution stage, a pressure-controlled, environmental-sealed dilution may be performed that is not subject to ambient pressure. Independently of different flows provided by the aerosol source, the same pressure is thus always regulated in the dilution stage. This can be achieved always defined, separated from the environment and other test conditions pressure conditions.

Also in the second dilution stage or the further dilution stages, a pressure-controlled, completed by the environment dilution can take place, so that correspondingly defined, separated from the environment and the other test conditions pressure conditions can be achieved.

Optionally, a classifier may be provided for classifying the particles in the particle flow. For example, the classifier may achieve particle size classification or size selection. Corresponding devices are known, for example a differential mobility analyzer - DMA. This makes it possible to eliminate a monodisperse aerosol with a desired particle diameter from the aerosol generated by the particle generator.

Since the pressures in the two dilution stages can be regulated independently of the ambient conditions, it is possible for flow control, for example by the DMA, to actively regulate the pressure difference between the two dilution stages, so that the flow thus established reaches the desired value.

Depending on the equipment of the system, it is thus possible, downstream of the dilution system (at the outlet of the particle source) to obtain a model aerosol with particles of defined size and with a set or known concentration. This can also be measured, characterized and controlled by means of the reference particle measuring device.

A vacuum pump may be provided to provide a vacuum for the dilution system. The vacuum pump can be the rotary vane pump already described above, which allows a regulated vacuum supply. Irrespective of different flows provided by the aerosol source (particle generator), the same pressure is always adjusted in the respective dilution stage. Thus, there are always defined, independent of the environment and other test conditions pressure conditions for the particle generator, the classifier and the reference devices and the device to be tested.

A venturi pump may be provided between the classifier and the second dilution stage. The Venturi pump can generate an additional positive pressure gradient and thereby control the flow through the classifier (DMA). The venturi pump can be particularly advantageous because it does not change the aerosol flow and, in particular, hardly any particles can be deposited.

A bypass to an outlet may be provided between the venturi pump and the second dilution stage. This allows a portion of the aerosol stream exiting the venturi pump to be diverted via the bypass and discarded via the outlet.

For a linearity test of the devices under test (the devices to be tested), the particle concentration often has to be varied widely, which is usually achieved by a strong increase in the dilution air flow. In this case, to reduce the particle concentration, a corresponding portion of the aerosol can be branched off and discarded downstream of the venturi pump and before the second dilution stage.

For the flow validation mode, a solenoid valve unit may be provided which is arranged in flow between the device to be tested, optionally the switching device (for example the ball valve switching device) and the reference gas flow measuring device, such that a gas flow between the switching device and the reference Gas flow meter is enabled via the solenoid valve unit. It can thus be achieved that, for the flow validation, the mass flow can be conducted loss-free via the reference gas flow measuring device. The solenoid valve unit is therefore realized to realize a plurality of gas paths and flow directions through a plurality of directional control valves. It is also possible that in the realization of a gas path, the solenoid valve unit is repeatedly flowed through in separate ways.

In the case of flow validation, the gas flow through the solenoid valve unit can either be routed through the ball valve switching device to the device under test (eg if this port on the device under test is also to be aerosoled in another mode) or directly from the solenoid valve unit to the device under test (if the connection to the device under test is needed exclusively for gas flow measurement). In the case of flow validation, reverse flow directions are also possible in each case, that is to say from the device to be tested to the magnetic valve unit in the test system.

In one variant, the ambient air can be supplied as gas flow via the magnetic valve unit to the reference gas flow measuring device and / or to the ball valve unit, wherein the ambient air gas flow can be supplied to the connection device after flowing through the reference gas flow measuring device via the magnetic valve unit and / or via the ball valve unit is for supplying the ambient air gas flow to the device under test or a component therein.

The reference gas flow meter may include one or more reference gas flow meters. In particular, the reference gas flow measuring device may comprise two different reference gas flow measuring devices, namely a first reference gas flow meter for small mass flows and a second reference gas flow meter for large mass flows. For example, small rivers can reach a maximum of 6 liters per minute, while large rivers can reach a maximum of 60 liters per minute. By providing the two reference gas flow meters, it is possible to reliably and accurately measure a wide range of mass flows.

The two reference gas flow meters (e.g., reference mass flowmeters - MFM - mass flow meters - or even reference volumetric flow meters) may also be inter-calibrated, that is, calibrated against each other, as will be explained later by way of one embodiment.

The entire test system can be designed in the form of a mobile unit. In particular, the unit can be accommodated in a frame, frame or cabinet which can also be displaced or, for example, moved on rollers. This allows all components to be housed in the rack or cabinet so that the system can also be used to test various devices and installations can be performed. It is therefore not necessary to take each time consuming construction and removal measures to check various devices to be tested.

The invention thus relates to a complete verification system for verification, i. Validation and / or calibration of particle measurement systems in terms of aerosol and flow validation.

In a particular embodiment, this can be done in particular under precisely defined and reproducible conditions in the entire test system and / or in one of its component groups, regardless of changing environmental conditions (pressure, temperature). The changing environmental conditions, for example due to the place of installation or the weather, have no influence on the accuracy of the measurement, since the pressure regulation of the flows takes place independently in a closed system.

A large number of flows, particle losses and aerosol measurement efficiencies of the particle measuring system to be validated or calibrated can thus be automatically controlled, measured and checked - as a whole and in subordinate parts. The described system significantly simplifies the technical problem of regular maintenance and calibration of particle gauges used in test benches. Due to the mobile arrangement of all components, it is very easy to carry out the automated test methods of both modes for testing the respective devices. This ensures a high standard of measurement accuracy for the user. The changes in the respective particle measuring devices, for example due to erroneous operations, can be reliably and automatically determined.

• - Ausgabe eines Gesamt-Resultats: z.B. Prüfling/System in Ordnung bzw. nicht in Ordnung (im Rahmen gegebener Grenzwerte)
• - Darstellung von problematischen bzw. fehlerhaften (Teil-)Komponenten, unter Umständen inklusive deren Lokalisation und Handlungsvorschlägen
• - Abschätzung ggf. erhöhter Fehler-Spannen auf Basis der Testergebnisse
• - Ausgabe von Faktoren zur Neujustierung von Komponenten im zum testenden Gerät. Unter Umständen direkte Neu-Justage des Systems oder der Komponente (Programmierung neuer Justagefaktoren) durch die Steuerung (6)
• - Ausgabe eines gesamten Kalibrier-Reports mit allen relevanten Ergebnissen, z.B. zum Nachweis der Konformität des zu testenden Gerätes in Bezug auf entsprechende Richtlinien oder Normen.

In one embodiment of the test system, it is possible to carry out (automatic) evaluation and / or reporting after passing through a selection or the entirety of the various tests. One or more of the following points may be taken into account:

• - Output of an overall result: eg test object / system in order or not in order (within given limits)
• - Presentation of problematic or faulty (sub) components, possibly including their localization and suggestions for action
• - Estimation of possibly increased error margins on the basis of the test results
• - Issue of factors for readjustment of components in the device under test. Possibly direct readjustment of the system or component (programming of new adjustment factors) by the controller ( 6 )
• - Output of a complete calibration report with all relevant results, eg to prove the conformity of the device to be tested in relation to corresponding directives or standards.

• 1 eine schematische Übersicht über ein Beispiel eines erfindungsgemäßen Prüfsystems zum Validieren bzw. Kalibrieren von Aerosol- und Flussmessgeräten;
• 2 eine detailliertere Darstellung des Systems von 1;
• 3 das System in der Aerosolvalidierungs-Betriebsart; und
• 4 das System in der Flussvalidierungs-Betriebsart.

These and further advantages and features will be explained in more detail below by means of examples with the aid of the accompanying figures. Show it

• 1 a schematic overview of an example of a test system according to the invention for validating or calibrating aerosol and flow meters;
• 2 a more detailed presentation of the system of 1 ;
• 3 the system in the aerosol validation mode; and
• 4 the system in the flow validation mode.

1 shows a calibration and validation system used as a test system 1 for validating aerosol and flow meters in a device to be tested connected to the system.

Most components of the system 1 are in a tempered cabinet 2 accommodated. The cupboard 2 For example, it can be mounted on rollers and thus easily movable to move it to the desired location for the respective calibration or validation operations.

At one on the cabinet 2 easily accessible connection device 3 is a device to be tested 4 connected. For this purpose, at the connection device 3 one or more lines may be provided, which - in the simplest case - have plug-in couplings, so that the corresponding line connections only need to be plugged.

Between the later explained components ball valve switching device 12 , device to be tested 4 and solenoid valve unit 16 in each case a plurality of parallel lines can be executed (for example, depending on a connection of the device to be tested 4 which can be individually selected by the switching means).

The device to be tested 4 is over the connection device represented by a symbolic box 3 with the system 1 in the cabinet 2 connected. It may be in the device under test 4 also to a larger plant, eg a Test bench, in which several measuring devices are provided, connected to the system 1 be connected to be checked by this.

If necessary, at the connection device 3 even more devices 5 be connected.

Furthermore, a control system controlling the entire system 6 intended. The control 6 on the one hand on the device to be tested 4 be provided. But it can also be part of the system 1 and in this case also in or on the cabinet 2 be housed. The control 6 can thus both the system 1 as well as the device under test 4 completely steer. The control 6 may also have independent sub-controls, each separately or coordinated with each other, the system 1 and the device under test 4 drive.

The control 6 is capable of all components of the system 1 to automatically execute the various operating modes. It is also possible to switch over the various operating modes by means of the controller 6 done automatically. It is thus possible after connecting the device under test once 4 with the system 1 via the connection device 3 Automatically perform all calibration and validation operations in one go, without the need for any operator to undertake any change or even refurbishment in between. The different steps are controlled by the controller 6 performed sequentially in any desired or suitable sequence, without intervention by an operator is necessary.

Below is the system 1 and the main components are explained:

A per se known particle generator 7 produces a polydisperse aerosol with a certain particle size distribution. Because of one in the system 1 existing pressure gradients, for example, by one or more in 1 not shown pumps can be generated, the particle aerosol flow flows into a dilution system 8th , in which the particle flow can be conditioned and diluted. This is the dilution system 8th dilution air 9 supplied from the outside. In addition, a classifier 10 be provided, which classifies the particles more precisely to be able to excrete a monodisperse aerosol with desired particle diameter can. The classifier 10 For example, it may be a per se known differential mobility analyzer (DMA) for particle size classification and size selection. The desired particle selection can be carried out, for example, by means of an electrostatic classification.

In the dilution system 8th For example, one or more, in the example shown here, two dilution stages may be provided. The design takes place as needed for concentration adjustment and flux increase.

Downstream of the dilution system 8th Part of the mass flow becomes an outlet 11 while another part to a ball valve switching device 12 (also: ball valve unit) is performed. The ball valve switching device 12 is part of a switching device for switching the gas flow in dependence on the desired mode of operation, which will be explained later, as well as the supply of the aerosol or flow to different points of the device to be tested 4 ,

The ball valve switching device 12 also allows a connection of a reference particle measuring device 13 , in the example shown, two reference particle measuring devices, a first reference particle measuring device 14 and a second reference particle gauge 15 having. The one to the reference particle gauges 14 . 15 guided mass flow can through a flow divider, not shown 13a be diverted.

The reference particle gauges 14 . 15 For example, you can use a Condensation Particle Counter (CPC) calibration, which uses condensation counters to count the counts of the connected device being tested 4 compared to the reference particle measuring devices 14 . 15 is compared.

The other part of the model aerosol, which is not the reference particle measuring device 13 is passed, passes through the connection device 3 to the device under test 4 and there eg to the particle measuring device inside the device to be tested 4 , By comparing the counts of the reference particle gauges 14 . 15 on the one hand and the device under test 4 or a particle sensor therein, the latter can be validated or calibrated. Thus, either the meter is in the device under test 4 alone against the reference particle measuring devices 14 . 15 validated or calibrated or it becomes the particle dilution and particle losses in the device under test 4 in the whole or in detail with measured.

Other measuring methods are also possible, for example a VPR calibration (Volatile Particle Remover) for detecting particle losses via components in the system to be tested via corresponding count rates at the input and output of the component (change through ball valve changeover device).

The first mode described above with its various tests may also be referred to as aerosol validation mode.

For the (automatic) execution of the flow validation mode serving as a second operating mode, the controller switches 6 the ball valve switching device 12 in a suitable manner, so that a connection of a terminal of the device under test to a solenoid valve unit 16 is created. In addition, direct gas paths between device to be tested and solenoid valve unit may be provided. The solenoid valve unit 16 has solenoid valves that can open and close different flow paths, depending on the control provided by the controller 6 , With the solenoid valve unit 16 is a reference mass flow meter serving as a reference gas flow meter 17 coupled in terms of flow, in which one or more later described reference mass flow measuring devices are provided.

The one in the flow validation mode by the reference mass flow meter 17 Guided gas or mass flow is measured there precisely and then to a - through the valve units (of the test system and the device to be tested) - serially connected flow measuring component in the device under test 4 led, where also takes place a measurement of this mass flow. In this way, this can be done in the device being tested 4 provided and there serving as a gas flow meter mass flow device by comparison with the results of the reference mass flow meter 17 be validated or calibrated. Sequentially, a selection or all of the flow measurement components in the device under test can be checked.

The flow direction of the gas flow can also be reversed. So it is possible that the gas flow first of all the measuring devices in the device under test 4 flows through and then through the system 1 is performed in this way to the measuring devices of the device under test 4 to check. Due to the design of the solenoid valve unit, a changeover of both flow directions is possible. In this case, the flow direction through the directional reference mass flow device can still be kept the same. Also, through the entire valve configuration, a review of other internal flow measurement components of the test system itself (eg, dilution air MFM) may be enabled.

2 shows a more detailed structure of the system 1 from 1 ,

In the aerosol validation mode, the particle flow passes from the particle generator 7 in a first dilution stage 18 where dilution air over a particle conditioner 19 is supplied. For better representation is in the 2 to 4 the dilution air flow is represented by bordered arrows, while the aerosol flow is symbolized by solid black arrows.

Downstream of the dilution step 1 is the classifier 10 (optional), behind which in turn a venturi pump 20 for generating a pressure gradient in the dilution system 8th is provided.

Downstream of the venturi pump 20 is a second dilution step 21 arranged.

To generate an aerosol flow and a pressure gradient necessary for this, there is also a pump 22 , For example, a rotary vane pump, provided a mass flow to the outlet 11 promotes. The pump 22 has appropriate connections to the first dilution stage 18 and to the second dilution step 21 ,

In addition, further supply of ambient air via a pressure reducer 23 and various mass flow meters (Mass Flow Meters - MFM) used as gas flow meters 24 be provided to monitor the respective gas or mass flows can. Thus, a complete control of the mass or aerosol flows is possible, so that finally a fully defined and controlled model aerosol flow 25 to the ball valve switching device 12 (Ball valve unit) is promoted.

The above-described provision of the model aerosol stream 25 ("Particle source") serves to clarify a concrete application example. The test system according to the invention (System 1 However, for checking aerosol measuring devices, any other source of particles may also be used to provide a particle flow (aerosol). It thus comes for the provision of the model aerosol stream 25 does not imply that a corresponding particle source has the structure described above.

In the aerosol validation mode, the ball valve unit leaves 12 the aerosol stream 25 in a simple way to the connections selected by means of ball valves on the device under test 4 as well as to the (also by ball valve) connected reference particle meter. That aerosol is here either in the ball valve switching device 12 or via an optional flow divider 26 divided up. Part of the aerosol flow passes through the connection device 3 to the device under test 4 and there to that in the device 4 integrated particle counter. Another part gets to one of the Reference Particle Size Analyzers 14 . 15 , eg to the first reference particle measuring device 14 so that the counts of the particle counter in the device under test 4 with the values of the first reference particle analyzer 14 can be compared.

Optionally, to further improve the accuracy even the second reference particle measuring device 15 be provided. Without further ado, the system can also be used with just one reference particle analyzer 14 operate.

For the flow validation mode, there is also a connection between the ball valve switching device, possibly having a plurality of line connections 12 and the solenoid valve unit 16 and optionally directly to the connection unit. About the solenoid valve unit 16 can thus ambient air to the reference mass flow meter 17 be guided, and then again about the solenoid valve unit 16 (and optionally via the ball valve unit) to the selected port of the device under test 4 be supplied.

The reference mass flow measuring device 17 has a first reference mass flow meter 27 and a second reference mass flow meter 28 on. The first reference mass flowmeter 27 For example, it may only be provided for smaller mass flows, for example up to a maximum of 6 liters per minute, while the second reference mass flow meter 28 may be provided for larger rivers up to a maximum of 60 liters per minute. By combining the two reference mass flowmeters 27 . 28 a broad dynamic range of mass flows can be covered.

3 shows the system 1 in the aerosol validation mode.

Since the individual components and their interaction already above on the basis of 1 and 2 no further comprehensive presentation to avoid repetition is necessary.

It can be seen, however, that the ball valve switching device 12 (Ball valve valve unit) is designed such that the model aerosol flow 25 via the ball valve switching device 12 and from there to the two reference particle measuring devices 14 . 15 and to the selected port of the device under test 4 is split.

The model aerosol flow 25 is generally provided by a source of particles. This particle source can be characterized by the in 3 shown components, in particular by the particle generator 7 and the dilution levels 18 . 21 be formed.

4 shows the system in the flow validation mode.

In this case, most of the components required for aerosol validation are unused and can be turned off accordingly. Only the ball valve switching device 12 is used to measure the measured mass flows to the device being tested 4 respectively.

The flow validation follows the following scheme:

First, ambient air is released from the inside of the cabinet 2 sucked. The (particle-free) ambient air flows through - depending on the flow strength selected by the solenoid valve unit 16 - One of the two reference mass flowmeters 27 . 28 (Mass Flow Meter) to determine the exact flow. From the output of the reference mass flow meter 27 . 28 becomes the now determined mass flow through the solenoid valve unit 16 and / or the ball valve switching device 12 into the device under test 4 initiated. The feeding of the flow takes place depending on the component to be examined on the device to be tested 4 On different parts. Accordingly, the connection device 3 different coupling points with the device to be tested 4 on, like in 4 recognizable. You may also in this context, further, in the device under test 4 existing valves or components are used or switched to direct the gas flow accordingly.

In the device to be tested 4 The injected gas or mass flow is possibly passed through defined valve contained therein and then measured using one of the existing sensors there. Subsequently, a comparison of the measured flows of the respective reference mass flow meter takes place 27 . 28 with the results of the sensors in the device under test 4 , Following this, an error can be detected and localized, or the sensors in the device under test can be detected 4 be corrected so that they get the measurement result of the reference mass flow meter 27 . 28 show measured flow.

Depending on the expected gas or mass flow (depends mostly on the device under test 4 ab) becomes either the first reference mass flow meter 27 or the second reference mass flow meter 28 each designed for specific flow rates, as discussed above. Of course, other limit values than those mentioned above are also conceivable, for example for the first reference mass flow meter 27 a flow of <1 liter per minute and for the larger second reference mass flow meter 28 a flow of> 1 liter per minute.

Depending on the component to be tested in the device under test 4 the gas or mass flow is at different points in the device under test 4 fed. Some ports in the device under test 4 are only via a detour via the ball valve switching device 12 reachable, as well as in 4 recognizable - especially if this connection is also used for tests in the aerosol validation mode. The flow paths are then in particular by switching the ball valve switching device 12 switchable accordingly.

To improve accuracy, there is also an intercalibration of the two reference mass flow meters 27 . 28 possible. The intercalibration, that is the mutual comparison of the devices 27 . 28 (Self-validation), according to the following scheme:

First, ambient air is drawn in from the inside of the cabinet, which is subsequently passed through the first reference mass flow meter 27 flows. Here is the determination of the exact flow. From the output of the first reference mass flow meter 27 the now determined flow becomes the second reference mass flow meter 28 initiated, where the measurement of the injected river also takes place. Below are the measured values from the first reference mass flow meter 27 and the second reference mass flow meter 28 compared. The result of the second reference mass flow meter 28 is determined by the result of the first reference mass flow meter 27 first validated and, if necessary, corrected (calibrated). The switching and realization of these gas paths and the serial flow through both reference mass flow devices 27 . 28 As well as the circuitry, it will affect various components of the device being tested 4 by the design of the solenoid valve unit 16 realized. Here, the gas flow can also be multiple times on separate paths through the solenoid valve unit 16 be directed.

Claims (12)

System (1) for checking aerosol and / or flow meters in a connectable to the system, to be tested device (4), with - A reference particle measuring device (13); a reference gas flow measuring device (17); - A connection device (3) for connecting the device under test (4); and with - A switching device (12) for switching a gas flow in response to a desired mode in different ways, namely + in an aerosol validation mode from a particle source (7, 8) to the reference particle measuring device (13), or + in a flow validation mode to or from a valve unit (16) with the reference gas flow meter (17); in which - In the aerosol validation mode, at least a portion of the particle-carrying gas flow generated in this mode by the reference particle measuring device (13) is guided and another part of the gas flow through the connection device (3) is guided, such that the gas flow also to the connectable to the connection device (3), device to be tested (4) can be guided; and where - In the flow validation mode at least a portion of the particle-free gas flow generated in this mode by the reference gas flow measuring device (17) and from or to the connection device (3) connectable, to be tested device (4) is guided. System after Claim 1 , wherein the connection device (3) has one or more lines to which the device to be tested (4) can be connected. System after Claim 1 or 2 wherein the particle source (7, 8) is for providing a gas flow particle flow for the aerosol validation mode. System after Claim 3 wherein the particle source comprises a particle generator (7) for generating particles. System after Claim 3 or 4 wherein the particle source comprises at least one of the following components: - a dilution system (8) for diluting the particle flow with dilution air; and / or - upstream of the dilution system (8), a particle conditioner (19). System after Claim 5 wherein the dilution system (8) comprises a first dilution stage (18) and at least a second dilution stage (21). System according to one of Claims 5 or 6 wherein the dilution system (8) comprises a classifier (10) for classifying the particles in the particle flow. A system according to any one of the preceding claims, wherein in the flow validation mode, the gas flow selectively includes a flow direction from the valve unit to the port device or, conversely, from the port device to the valve unit. A system according to any one of the preceding claims wherein there is provided for the flow validation mode a solenoid valve unit (16) serving as a valve unit, fluidly disposed between the device under test (4), the switching means (12) and the reference gas flow meter (17) such that a gas flow between the switching device (12) and the reference gas flow measuring device (17) via the solenoid valve unit (16) is made possible. System after Claim 9 , wherein - ambient air is supplied as a gas flow via the solenoid valve unit (16) to the reference gas flow measuring device (17) and / or to a ball valve unit (12); and wherein - the ambient air gas flow, after flowing through the reference gas flow measuring device (17) via the solenoid valve unit (16) and / or via the ball valve unit (12) to the connection device (3) can be supplied to supply the ambient air gas flow to the Device to be tested (4). A system according to any one of the preceding claims, wherein the reference gas flow meter (17) comprises at least two different reference gas flow meters, namely a first reference gas flow meter (27) for small gas flows and a second reference gas flow meter (28) for large gas flows. A system according to any one of the preceding claims, wherein the system (1) is in the form of a mobile unit (2).

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