All HF Type Filters are subjected to extensive testing during development, manufacturing and assembly, in addition to the final tests in which every single filter is tested in order to ensure superior quality.

The following report is a summary of the basic performance tests each filter has to withstand. For additional data contact your local supplier.

The BE Performance Tests are executed in the factory's modern test laboratories as well as by the Standards Institution of Israel and the Israeli Institute for Biological Resarch.

The BE Performance Tests are based on the Israeli and Swiss Standards as minimum requirements and in many cases exceed them. Beside the tests described herein, there are numerous other specific performance tests in the scope of ensuring proper function of the filters in all extreme conditions.

The tests presented in the following are the most important test procedures, called "The Basic set". They include:

1. Absolute Filter Efficiency
2. Tightness
3. Pressure drop
4. Channeling
5. Moisture determination
6. Blast Wave Durability
7. Shock Durability
8. Rough Handling Durability
9. Coating

In the following pages we will present the test procedures and methods of measuring the "Basic set", according to the following scheme.

Each test procedure contains the following subparagraphs:

a) Definitions
- Background information on the necessity of the test
- Analysis of measurement and units

b) Passing criteria
- Required values supported by different National Standard Institutions (Israeli / Swiss Standard Institutions, DIN, ISO, etc.).
- BE applicable passing criteria for each test.

c) Test procedure
- Test description
- Test data

In addition the these tests, there are numerous other test performed in-house and / or in suppliers' laboratories and / or in independent laboratories such as:

- The Standards Institution of Israel
- Israel Institute of Biological Research (IIBR)
- Swiss Federal Office of Civil Defense (BZS)

Other tests not mentioned but also performed are

1. For the HEPA-filter material

- MD - Tensile strength
- CD - Tensile strength
- MD - Elongation
- CD - Elongation
- MD - Folded tensile
- MD - Gurley Stiffness
- Ignition loss
- Water repellency
- Alcohol Drop test

2. For the activated carbon

- Ag, Cu, Cr, Zn - Content
- Specific surface check
- Ballpen Hardness
- Moisture
- CK - Adsorption (Chemical Adsorption)
- Aging under humid conditions
- Accelerated aging test for simulation of long time aging

The tests are made according to the Israeli and / or Swiss Standards.
Specific tests reports are published in specific issues.

The absolute filter is tested in an Absolute Filter Test Device defined by BS EN1822. The paraffine test particles are generated by an Aerosol-Generator. A high sensitivity laser particle counter measures the eupstream and downstream concentration. The penetration is calculated as the ratio of downstream concentration to upstream concentration under nominal airflow.

Efficiency = 100% - Penetration

The HF Type Filters are checked according to the Israeli and Swiss Standards.

The Israeli Standard demand as a maximum:
- 2000 Pa for filters used in systems with generator back-up

For filters in systems with manual or battery back-up:
- 600 Pa for filters up to 180 m³/h
- 800 Pa for filters over 300 m³/h

The Swiss regulations demand as a maximum:
- 600 Pa for filters up to 300 m³/h
- 800 Pa for filters with 600 m³/h

The Pressure drop for all sizes of the BE-Filter Units Type HF may not exceed:
- 600 Pa for all kinds of filters in systems with manual or battery back-up
- 1000 Pa only for filters in systems with generator back-up.

The pressure drop and airflow is measured according to ISO 5167-1.

All HF Type Filters are changed at the inlet with 1000 PPM (1 PPM = 1 x 10-6) simulation gas in order to achieve 0% failure! the concentration at the filter outlet may not exceed 800 PPB (1 PPB = 1 x 10-9)

According to Israeli and Swiss Standard the carbon humidity of a ready-to-use filter may not exceed 5%

A well defined sample of the carbon in use is placed in an oven with 120º C for at least 3 hours. After cooling down within a convenient deseccator, the moisture is calculated by comparing the initial weight with the final (dried) weight. Normal moisture-values in HF Type Filters are around 2%.

The Swiss regulation demands exposure to a blast-wave with a peak excess pressure of 10 kPa and an impulse of 150 Pa x s. The filter may not show any failure.

The HF Type Filters are connected to a blast valve which is mounted onto the BE-shock tube. For testing the Blast Wave Durability the Filter Unit is exposed to the penetrating pressure peaks of 4 consecutive blast waves according to the Swiss regulation. Checking again according paragraph - 4, no failure is acceptable.

Israeli Regulations:

max. velocity:            1.5 m/s
max. acceleration:      60 m/s² = 6 g
number of shocks:      9

Swiss Regulations:

max. velocity:            0.63 m/s
max. acceleration:      63 m/s² = 6.3 g
number of shocks:      6

The HF Type Filter is mounted onto a shock-test machine in a position to simulate its typical mounting position in a shelter and is tested under the above-mentioned conditions. No effects on proper operation may appear.

In addition as an alternative test the HF Type Filter is exposed to vibrations of 10 g for a duration of 1 min.

No signs of damage may appear on the Filtre Unit.

The test is performed according MIL-STD-282 Method T105.10. The vibration machine generates 200 shocks per minute with an amplitude of 20 mm.

is mounted onto the vibration machine. The test is performed according to MIL-STD-282 Method T105.10 for a duration of 15 min.

No effects on proper operation may appear.

According to Swiss Regulations the coating of Filter Units must have a thickness of at least 60 µm. The parts that have been treated with surface coating must not show any signs of corrosion after stroge for a period of 2 weeks in a slat-water mist (3% NaCI solution). The cross cut test according to ISO 2409, may not exceed class 2. The coating of the parts being is contact with warfare materials has to be resistant againts those materials.

The HF Type Filters are first phosphatized (1 µm) and are then coated with a 90 µm Polyester-Exoxy coating.

No signs of corrosion may appear after a storage of 2 weeks in a salt-water mist. (A 5% NaCI solution is used to simulate the environment of coastal countries.) The cross cut test is performed according to ISO 2409.