Tiêu chuẩn iso ts 19713 2 2010

Microsoft Word C055621e doc Reference number ISO/TS 19713 2 2010(E) © ISO 2010 TECHNICAL SPECIFICATION ISO/TS 19713 2 First edition 2010 07 15 Road vehicles — Inlet air cleaning equipment for internal[.]

Measurement accuracy

Accuracy requirements are given in Table E.1

Copyright International Organization for Standardization

Test stand configuration

Vehicle manufacturer air cleaner assemblies and individual air filter elements can undergo testing The test stand is composed of several key components, organized as illustrated in Figure 2.

NOTE 1 Results can vary depending on configuration

NOTE 2 Air cleaner assembly orientation will affect performance It is advisable that air cleaner assemblies be oriented and tested as installed in the vehicle

Figure 2 shows a set-up to measure the performance of an air cleaner assembly

Figure 3 shows a recommended air cleaner housing to measure the performance of a panel-type air filter element

Figure 4 shows a recommended air cleaner housing to measure the performance of a cylindrical-type air filter element

The test procedure focuses on evaluating air cleaner housings that include filter elements or are designed to accommodate them, specifically those with tubular inlet and outlet connections While pre-cleaners may be part of the unit under test, systems lacking these tubular connections, such as perforated or louvered inlets, can be assessed if placed within a plenum featuring a tubular inlet Any non-tubular air cleaner systems can be evaluated upon mutual agreement between the tester and the customer.

Air cleaner assemblies shall be evaluated using the set-up shown in Figure 2

4.2.2.3 Evaluating panel air filter elements

In general, panel-type air filter elements may be tested using the recommended housing shown in Figure 3

4.2.2.4 Evaluating cylindrical/round air filter elements

Figure 4 shows a recommended housing to test cylindrical-type air filter elements This housing design is similar to the one recommended in ISO 5011

Upstream and downstream cylindrical ducting shall be made of conductive material and all components shall be commonly grounded from the aerosol inlet section to the downstream sampling section

Inlet air must be conditioned to meet ISO 5011 standards, specifically at a temperature of (23 ± 5) °C and a relative humidity of (55 ± 15) % Additionally, a HEPA filter is required for the inlet air if the background particle concentration surpasses the levels specified in Annex E.

The ducting for air testing can be configured vertically, horizontally, or in a combination depending on available space, with a vertical setup being recommended This procedure illustrates a vertical configuration for testing air cleaners and panel-type air filters It is ideal to position particle samplers vertically in each test section to minimize particle loss and facilitate the sampling of larger particles The design of the test system aims to reduce particle losses while adhering to the specifications outlined in Tables E.1 and E.2.

The test system must accommodate user-defined flow rates while ensuring that these rates are maintained despite an air cleaner assembly pressure loss of up to 10 kPa Duct sizing should adhere to the "nominal" duct diameter and Reynolds numbers specified in Table 1, with adjustments made for higher or lower flow rates by scaling the duct sizes accordingly.

Table 1 — Duct diameter versus flow range

Nominal duct diameter Area Velocity Flow range low

Flow range high Reynolds number mm m 2 m/s m 3 /h m 3 /h at low flow at high flow

A 10 µm particle with a specific gravity of 2 settles in still air at a velocity of approximately 6 × 10^{-3} m/s At a minimum velocity of around 5.1 m/s, this particle would experience a 10 mm drop over a distance of 3 meters.

Test inlet airflow shall be filtered with a HEPA filter to remove the majority of ambient aerosol, if required, in accordance with Annex E

The test system must ensure consistent and stable airflow to the air cleaner assembly or the air filter element being tested, as specified in the test setup.

Uniform airflow is essential in areas with isokinetic samplers when assessing air cleaner assemblies, as it ensures that a representative aerosol sample is collected For detailed guidance on flow uniformity measurements, refer to section 4.2.10.4.

It is important to minimize leakage into the test system to obtain valid data Depending on where the leakage occurs, it can cause major errors in particle counting

To ensure safety and efficiency, it is essential to visually inspect all connections and joints for leaks using a soap solution Applying the soap solution with a brush at these points is recommended, particularly on the clean side of the air cleaner, where leaks can have significant consequences.

4.2.10 Fractional efficiency test aerosol generator

The aerosol generator used for fractional efficiency tests must ensure a stable and uniform aerosol concentration and size distribution It is essential that the aerosol's size distribution contains enough particles for statistical evaluation in each size class, as detailed in B.6 When utilizing high-resolution particle spectrometers, size classes can be combined to meet the necessary particle counts Additionally, the total aerosol concentration in the test duct must not exceed the limits set for the particle counter specified in section 4.2.14.3 To maintain accuracy, the aerosol concentration during efficiency tests should be low enough to prevent any changes in efficiency, thereby avoiding loading effects as outlined in Clause 5.

Test dust and aerosol generation shall be in accordance with ISO 5011:2000, 6.2.1 to 6.2.5

The efficiency test aerosol should be injected with the airflow in accordance with Figure 2 (see ISO 5011:2000, 6.2.1 to 6.2.5)

During the validation of the efficiency test aerosol's uniformity and concentration, it is essential that no air cleaner is installed at the test filter location; instead, a smooth pipe or elbow may be utilized The particle size distribution and concentration of the test aerosol for fractional efficiency tests can be verified using a particle-sizing instrument, which will sample upstream and downstream of the air cleaner mounting position with isokinetic samplers Evaluations will be conducted at minimum and maximum flow rates, with samples drawn at three specific locations along the duct diameter: 0,15 D, 0,5 D, and 0,85 D Measurements will occur in a plane along two perpendicular diameters, with a minimum of three samples taken at each location, and the resulting number distribution averaged To ensure accuracy, samples should be collected randomly, and the average values for each particle-size range must not vary by more than ±10% for particles less than 15 µm and ±20% for larger particles across the five locations This process confirms that the efficiency test aerosol is uniformly distributed within the test duct, making the centerline sample representative of the overall challenge.

NOTE For tube diameter D, the sampling positions are the following:

Figure 1 — Location of isokinetic sampling points for validation

4.2.11 Aerosol neutralizer for coarse test dust

Neutralization is not used in this part of ISO/TS 19713

4.2.12 Upstream and downstream sample probes

Sampling probes must be isokinetic, ensuring the local velocity of the duct matches that of the probe within ±20% The same probe design should be consistently used both upstream and downstream of the filter, with probes positioned on the duct's centerline They should be placed at least seven diameters downstream and four diameters upstream of any bends, reducers, or expanders Probes must be constructed from electrically conductive metallic tubing with a smooth interior to minimize particle losses, and their inlets should be sharp-edged and centrally located Upstream and downstream sampling lines should be identical, straight (with no more than one bend), and as short as possible A short flexible connection (up to 50 mm) to the particle counter is permissible to reduce stress on the counter inlet, but PTFE should not be used; instead, conductive tubing like plasticized PVC is recommended For further details on isokinetic sampling and tubing specifications, refer to Annex G and the Bibliography.

Sampling probe ducting to the particle counter must be set up in a way that no sedimentation of large particles takes place, i.e

⎯ vertical orientation of the tubing;

⎯ short connection length between n particle counter and sampling;

⎯ avoidance of bends in the tubing;

⎯ no sharp angles if bends are necessary

4.2.13 Loading test aerosol generator (see ISO 5011)

Aerosol generation shall be in accordance with ISO 5011:2000, 6.2.1 to 6.2.5 (See also 4.2.10.)

4.2.13.2 Loading test aerosol (air cleaner assembly only)

A dust injector (see ISO 5011:2000, Figure B.2 or B.3) shall be used to disperse the loading test aerosol (ISO 12103-1 test dust) The dust feeder location is shown in Figure 2

4.2.13.3 Loading test aerosol dust feeder

A dust feeder capable of feeding a stable (within ±5 %) concentration of 1 g/m 3 of air at the test flow rate shall be used Reference the dust feeder specifications and validation procedure in ISO 5011

4.2.14 Upstream and downstream particle counter

For optimal performance, both upstream and downstream particle counters should be of the same model and closely matched A single particle counter can effectively measure efficiency through sequential measurements It must be capable of detecting airborne particles within the geometric size range of 5 µm to 40 µm and should be able to distinguish at least eight logarithmically spaced particle size classes.

The particle counter must be calibrated using polystyrene latex particles of suitable size or other appropriate standards before system start-up and at least annually to ensure size calibration remains accurate Additionally, it is advisable to periodically verify the calibration of the particle counter throughout the year between scheduled calibrations.

To prevent coincidence counting in particle measurements, it is essential to establish a maximum total particle concentration This limit can be determined by conducting filter efficiency tests at various concentrations and analyzing the results The maximum concentration is identified when doubling the concentration results in a fractional efficiency drop of more than 5% in the smallest size range Alternatively, one can increase the concentration in steps, using both diluted and undiluted aerosols, to find the point at which the particle measurement device shows significant deviations from expected values in the smallest size range An example of this process is provided in Annex D.

The particle measurement device flow rate shall remain constant within ±5 % for the duration of a test including the correlation done before the test

4.2.14.5 Upstream/downstream particle counter correlation ratios

Test conditions

All tests shall be conducted with air entering the air cleaner assembly or air filter element in accordance with

4.2.4, with the permissible humidity variation throughout one single test being ±2 %

For this part of ISO/TS 19713, the KCl (potassium chloride) test aerosol shall be used

For this part of ISO/TS 19713, the following test dust shall be used:

⎯ for single-stage air cleaner assemblies and air filter elements: ISO 12103-1 A2 test dust;

⎯ for pre-cleaners and multistage air cleaner assemblies: ISO 12103-1 A4 test dust

Before a test, condition the dust in accordance with ISO 5011

A HEPA filter ensures clean air supply to the test stand when necessary, while a high-efficiency filter can be utilized downstream to safeguard the flow meter and air-moving devices.

Validation

Prior to initial use, the test stand shall be validated in accordance with Table E.2

Any modifications to the hardware or components of the test setup require a thorough re-verification and re-evaluation of the affected portions of the test stand.

The validation certifying the performance of a system in accordance with this part of ISO/TS 19713 shall be documented, including the following: a) system diagram and detailed description:

⎯ particle materials used in the tests including traceability;

⎯ manufacturer and model of the particle measurement device;

⎯ calibration data for the particle counter(s);

The article outlines essential calibration and performance data for flow measuring devices and pressure transducers, emphasizing the importance of flow and particle concentration uniformity It includes evidence that the coincidence counting error aligns with established criteria, as well as data reflecting the agreement between upstream and downstream particle counters in both single and dual-counter systems Additionally, it highlights that the aerosol concentration during efficiency tests is sufficiently low to prevent loading effects on unloaded filter elements The article also presents sample test data, demonstrating the repeatability of results and quantifying particle loss for larger particles within the sampling system.

Routine operating procedure

To ensure ongoing accuracy as outlined in Annex E, specific start-up procedures must be conducted periodically to confirm the proper functioning of the test system These procedures encompass a range of activities necessary for verification.

⎯ verification of particle counter operation such as flow rate and zero count (Table E.3);

⎯ measurement of background particle count in the test duct with no test filter and no test aerosol;

⎯ correlation of upstream and downstream particle sampling and measuring systems;

⎯ check zero on pressure measurement devices

See, for example, Table E.3 The reference air cleaner assemblies or air filters will be used for daily checks of system performance

General

The purpose of this test is to determine the particle collection capabilities of the filter This test is conducted with constant airflow rate using the aerosol described in 4.2.10

Test procedure

Continuously monitor temperature and relative humidity while setting the specified volume flow rate and measuring tare pressure loss without an air cleaner or filter in the test stand After any changes in the test setup, perform necessary calibrations as outlined in Annex E Install the air cleaner assembly or air filter element in the designated test housing according to Figures 2, 3, or 4, and test the assembly as it would be in the vehicle Stabilize the air cleaner assembly or filter element to the required temperature and humidity conditions at rated flow for at least 15 minutes before measuring the pressure loss (∆P i) of the new filter Begin feeding the efficiency test aerosol as specified and wait for the upstream aerosol to stabilize, while ensuring the dust feeder is set to the required dust mass flow.

NOTE The particle counts upstream should be within ±5 % of the average of three measurements j) Determine the fractional efficiencies by particle counting as follows:

To measure filter efficiency in sequential counting systems, begin by connecting the counter to the upstream sample probe and allow the sampling system to equilibrate before counting the upstream particles Next, switch to the downstream sample probe, wait for equilibration, and count the downstream samples This upstream-downstream cycle should be repeated two additional times, resulting in three upstream and three downstream samples Finally, calculate the filter efficiency for each of the three samples.

For effective simultaneous counting systems, it is essential to count and record particles from both upstream and downstream This process should be repeated two additional times, resulting in three samples from both upstream and downstream Subsequently, calculate the filter efficiency for each of the three samples.

To ensure accurate filter efficiency measurements, follow the procedure outlined in Annex B for data reduction Monitor the three filter efficiency measurements for any trends, as efficiency can fluctuate with filter loading High aerosol concentrations may skew results, making it essential to reduce the concentration if measurements differ by more than ±5% in the 5 µm particle size class, rendering the test invalid After adjusting the aerosol concentration, initiate a new test with a fresh filter If no significant trends are observed in filter efficiency throughout the tests, calculate the average efficiency of the unloaded filter element For subsequent loading or incremental fractional efficiency tests, proceed immediately after completing the efficiency test; otherwise, calculate the results if only the pre-loading fractional efficiency test is necessary.

To ensure accurate measurements, begin or resume feeding the loading dust until the pressure loss across the filter reaches the second incremental pressure loss Next, measure the incremental fractional efficiency using particle counters Continue this cycle of measuring fractional efficiency and loading until the final pressure loss and fractional efficiency are obtained Calculate the efficiency and confidence limits for each particle size range and loading increment as outlined in Annex B If the smallest number count exceeds 500, efficiency can be calculated without upper and lower confidence limits Finally, include the minimum required information in the report, as detailed in Annex A, and consider using the form provided in Annex A to present the results.

Engine air cleaners for light, medium and heavy duty vehicles

Manufacturer: Type of filter media: Air cleaner description and orientation: Air filter description and orientation: Pre-cleaner/pre-separators:

Test duct set-up and orientation

Dust feeder: Contaminant for efficiency measurements (ISO 12103-1 A2/A4 test dust)

Contaminant for loading (ISO 12103-1 A2 test dust) Equipment: Settings/feed rate: Particle counter: Type: Sample flow:

The test flow rate was measured in cubic meters per hour (m³/h), with specific termination criteria established Temperature readings were taken before and after the test, recorded in degrees Celsius (°C) Barometric pressure was noted in kilopascals (kPa) before and after the test, alongside relative humidity percentages (%) at both time points Total cumulative counts were documented in counts per cubic centimeter (counts/cm³), with the test termination pressure also specified in kPa Additionally, fractional efficiency intervals and initial restriction values were recorded in kPa.

X optical particle diameter, in àm

Y fractional filtration efficiency, in percentage

Figure A.1 — Fractional efficiency as a function of particle size and dust capacity at test flow rate

Figure A.2 — Pressure loss versus aerosol loading

When evaluating fractional size filtration efficiency with particle counters, it is crucial to acknowledge the limitations of this method Efficiency is assessed by comparing the number of particles detected upstream and downstream of the air cleaner or filter However, discrepancies often arise between the sampling and detection equipment used in these two locations This article introduces a method for calculating correlation ratios to reduce errors stemming from these differences Additionally, the correlation ratio can be utilized to adjust for unequal sample times between upstream and downstream measurements.

When particle counts in any size class are low, errors may arise from counting random events This article presents a method to quantify potential counting errors, emphasizing the importance of using actual particle counts rather than concentrations or averages In the efficiency tests outlined, three upstream and three downstream samples are counted, and their totals are combined for each size class These totals are crucial for accurate calculations, as relying on average counts can lead to misleading confidence limits.

Data reduction techniques focus on the correlation between upstream and downstream sampling and counting, as well as the statistics of counting a limited number of particles However, the confidence intervals derived from these methods may not accurately represent the overall test accuracy or precision While the test's accuracy and precision cannot exceed the confidence interval based on counting statistics, they may be compromised due to unaddressed sources of error To reduce these additional errors, it is crucial to qualify and calibrate the test system as outlined in Clauses 4 and 5.

Clauses B.2 to B.5 provide straightforward calculations, while Clause B.6 offers additional details, including a sample calculation These calculations focus on penetration, defined as the ratio of particle concentration downstream of the filter to that upstream After completing the calculations, penetrations can be converted into efficiencies, and the process is repeated for each relevant particle size class.

The symbols and subscripts in B.1.2.1 and B.1.2.2 are used in equations in this annex

In the context of statistical analysis, the following subscripts are defined: \(o\) represents observed values, \(ucl\) denotes the upper confidence limit, and \(lcl\) indicates the lower confidence limit The term \(spec\) refers to specified performance, while \(c\) signifies correlation without a filter installed Additionally, \(t\) is used for testing a filter, with \(uc\) indicating upstream during correlation and \(dc\) representing downstream during correlation For testing, \(ut\) denotes upstream and \(dt\) indicates downstream.

Using counts obtained with test filter replaced by a straight vertical tube, the observed correlation ratio should be calculated for each size class as shown in Equation (B.1): o,c o,dc o,uc

NOTE Any dilution system to be used for the measurement also needs to be present for the correlation ratio measurement

B.2.2 Upper confidence limit and lower confidence limit values — Correlation ratio

B.2.2.1 For numbers N u 50, Table B.4 should be used to determine the 95 % upper and lower confidence limits for each size class for the upstream and downstream counts with no filter installed

B.2.2.2 For numbers N > 50, use Equation (B.2) to determine the upper and lower confidence limits for each size class:

EXAMPLE N ucl,dc = N o,dc + ( 2 × N o,dc )

Equations (B.3) and (B.4) calculate confidence limits on the correlation ratio: ucl,dc ucl,c lcl,uc

= N (B.3) lcl,dc lcl,c ucl,uc

With the test filter installed, upstream and downstream counts should be obtained to calculate the observed penetration for each size class, as shown in Equation (B.5): o o,dt o,ut o,c

B.3.2 Upper confidence limit and lower confidence limit values — Penetration

To calculate the upper and lower confidence limits for upstream and downstream counts in each size class, refer to Table B.4 for counts \(N \leq 50\) and use Equation (B.2) for counts \(N > 50\) Additionally, the upper and lower confidence limits for penetration in each size class should be determined using Equations (B.6) and (B.7).

= × (B.6) lcl,dt lcl ucl,ut ucl,c

B.4 Calculations for unequal sample times

If Equation (B.8) is true, then no adjustments for sampling time needs to be made: uc ut dc dt

If the condition in Equation (B.8) is not met, then the calculation for the observed penetration is as shown in

Equation (B.9): ut o,dt o dt o,dc uc o,ut o,uc dc

The upper and lower confidence limit values for penetration are calculated using Equations (B.10) and (B.11) The results are denoted as ucl,dt, ucl, ut, dt, lcl,dc, uc, lcl,ut, and ucl,uc, dc.

(B.10) lcl,dt lcl ut dt ucl,dc uc ucl,ut lcl,uc dc

The efficiency for each size class is calculated from the penetration, as shown in Equations (B.12) to (B.14): o 1 o

When a stable aerosol passes through a filter, particles will randomly appear downstream at an average population density A particle measurement device detects these particles over time, providing an average rate of detection To calculate penetration, this average rate, expressed as particles per unit time or volume, is derived from the cumulative counts recorded during the testing period or the sampled volume.

As filter penetration decreases, the significance of particle counting statistics rises, with variations explained by Poisson statistics A key aspect of this testing is understanding the correlation between a single test result and the true mean result that would emerge from an infinitely long test This relationship, along with the confidence limits on the true mean, is well-documented in the literature.

Tiêu đề	Technical Specification Iso/Ts 19713-2
Trường học	International Organization for Standardization
Chuyên ngành	Standardization
Thể loại	Tiêu chuẩn
Năm xuất bản	2010
Thành phố	Geneva

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