Lab testing systems for respirator masks acc. to EN 149

For the laboratory test station, great importance is attached to strict compliance with all standard specifications according to DIN EN 149 and DIN EN 13274-7.

The test station is equipped with separate filter test chambers for testing the permeability to NaCl and to paraffin oil (PAO). The mask is manually fixed onto a holder with which it can then be placed into the filter test chambers. In addition, the station is equipped with a Sheffield probe in the third test position, which can be swivelled into any position.

The permeability is determined by means of a flame photometer for the NaCl aerosol and an optical photometer with diluent for the PAO. The aerosol generators are designed to provide sufficient power for the exposure test specified and described in DIN EN 13274-7.

For each one, the aerosol concentration is measured both upstream and downstream of the mask.

As specified in EN 149 and 13274-3, the breathing resistance is measured by means of a Sheffield probe which can be placed into the various positions of use. Here, exhalation volume flows of up to 300 l/min and inhalation volume flows of up to 120 l/min are possible.

It is also possible to set up other default and limit values corresponding to various international standards.

The test is automated in sequences. Due to the variety of testing possibilities, the operators should be appropriately trained personnel.

The test results can be stored locally on a USB flash drive or on a network.

Based on DIN EN 13274-1, we have developed the test system shown opposite, which can of course be adapted to the available space according to customer specifications.

It is equipped with an adjustable ventilation system with aerosol generator for NaCl and flow measurement technology. In the example shown, a homogeneous aerosol field of 1000 mm x 1000 mm is created in which the test person can perform the prescribed activities.
The measurement of the respiratory activity and the clocked sampling under the mask as well as sampling in the cabin are controlled by means of a PC, which also operates the flame photometer.

We can either provide assistance for the dimensioning of the cabin, the selection of the treadmill and the dimensioning of the ventilation technology or we deliver the complete system.

The dimensioning of the aerosol generation will be based on this. We will supply the entire measurement technology ready for installation, including the PC for controlling the test sequences. Due to the variety of tasks the test persons have to perform, the personnel responsible for operation and supervision of the test persons should be appropriately trained.

The test results can be stored locally on a USB flash drive or on a network.

The test system shown opposite has been developed based on DIN EN 149 and in accordance with DIN EN 13274-6. It can be used to test the accumulation of carbon dioxide under the mask according to the standards.

The Sheffield probe is used to exhale air with 5% added carbon dioxide through the mask. In front of the mask, the exhaled air is removed by a flow channel which is set to a defined air flow and a fixed maximum concentration of carbon dioxide.
During inhalation, a sample of the air is taken and analysed for residual carbon dioxide.
The test station is supplied as a complete assembly including all components and is equipped with the artificial lung with auxiliary lung, the technology required for mixing the carbon dioxide, carbon dioxide sensors of the required accuracy and the necessary valve technology.

All values can be monitored on the control panel and adjusted to be within the required set point range.

The test is done semi-automatically. Which means that the tests have to be performed by appropriately trained personnel.

The test results can be stored locally on a USB flash drive or on a network.

The conditioning is carried out according to DIN EN 149, 8.3.1

The system is installed on its own workbench and consists of

• an artificial lung with adjustable stroke and stroke frequency according to EN 13274-3 Table 1
• a humidifier (not suitable for medical use) with adjustable temperature and water level warning light
• an inclined Sheffield probe (for draining condensate) with sensors for recording humidity and temperature in the “mouth” and “throat” areas
• a console PC in a stainless steel housing with software to define the settings and carry out the conditioning, including recording of temperature and humidity at the end of each exhalation cycle and measurement of the maximum pressure during the exhalation process.

During the preset measuring period, the cycles are counted and the average values of the measured values determined. These are saved together with the test item identification as a .csv file after completion of the test.

The test item identification can be done by means of a barcode reader with serial interface or by manual input.

The process is fully automatic. The system can also be operated by semi-skilled personnel.
The process data can be stored locally on a USB flash drive or on a network.

This system comprises the laboratory system for conditioning and a dust test chamber according to DIN EN 13274-8. In combination with suitable holders, it can also be used for clogging (dust loads) prescribed in EN 143, EN 405, EN 12083, EN 14387 (with constant volume flow), EN 149, EN 1827 (with respiration using humid air), EN 12491 and EN 12942 (with respiration using dry air).

In a defined dust atmosphere, the mask is exposed to the load prescribed by the respective standard until the specified disposition time or quantity is reached.

The test uses dolomite dust that is atomised by means of a turbulator and moved through the dust test chamber at a predetermined speed.
The Sheffield probe (or another filter or mask holder) connected to the artificial lung (with or without humidification) or to a constant volume flow source is installed at the prescribed test position in the chamber.

The process is automated so that the device can be operated by semi-skilled personnel.

The process data can be stored locally on a USB flash drive or on a network.