Due to the current need for facial protection, measuring setups are required to determine the safety of a large variety of facial masks. This report describes the setup of a dry particle test. This test can be used to determine the filtering capabilities of the mask for different particle sizes from 0.3 um to 10 um.

Equipment

  • SOLAIR 3100 Particle counter
  • The setup shown in the following figure:

Setup

The setup consists mainly of 2 parts, the SOLAIR 3100 particle counter and the particle chamber illustrated above. These must be connected using a tube, via the outlet pipe of the particle chamber and into the inlet on top of the SOLAIR 3100. Preferably, this tube should be an anti-static tube such that little to no particles stick to the tube. Such a tube is provided with the SOLAIR 3100. On top of the particle chamber a mask can be placed which is then pressed against the O-ring using the plexi-glass lid. This plexi-glass lid can be fastened using the nuts and knob. Note that the height can be adjusted to fit and secure the particular mask in question, only make sure that the plexi-glass does not break by raising and lowering the nuts. The data is printed by the SOLAIR 3100.

Please view the following pictures for a clear illustration of the setup.

Method

At the start of the morning, afternoon or evening the machine must be cleaned using the zero-pass filter. This is the large white cylinder supplied with the SOLAIR 3100. The zero-pass filter is attached to the inlet of the SOLAIR 3100. The machine is then turned on by pressing ‘START’ on the touchscreen of the SOLAIR 3100. This process needs to run for 5-10 minutes depending on the particle cleanliness of the environment (heavily contaminated environments require longer durations for testing). Note that this step has to be repeated more often to correct for high particle density environments.

For each mask the process is the same. First a reference test/count of the environment particles is performed. This measurement is done without a mask. The test is started by pressing ‘START’ and will run for 60 seconds. The measurements are printed, however the paper is not ripped. This is done after the full test has been completed.

For the next step the right side of the mask is placed between the lid and pot and the lid is tightened. The machine is then started again. Once the machine prints the results, the left side of the mask can be tested.

When this is done, the paper can be ripped from the machine and secured to the mask or placed in the same bag.

Test protocol:

Required software:

  • LMS Express 8 (optional if you want to download the data to your computer directly).

Preperation:

  1. Plug the SOLAIR 3100 into the wall socket and turn on with the button on the front of the machine.
  2. Fasten the zero filter to the top of the inlet on the top of the machine as shown in the figure below.
  3. Turn on the machine and wait between 5-10 minutes (depending on the particle density in the environment) and ensure the values are stable at 0.
  4. When done, the zero filter can be removed, and the tube can be secured to the inlet on top of the machine.
  5. The other end of the tube is connected to the pot. Make sure these connections fit snugly.

Test:

  1. Start the machine measurement without any mask in the setup. Wait until the data has been printed at the bottom of the machine (SOLAIR 3100). It should be in the form of a receipt.
  2. Secure the mask onto the pot such that the left side of the mask is over the hole.
  3. Place the plexi-glass over the mask such that the tab pertudes into the block on the left of the pot setup.
  4. Tighten the screw such that the mask is securely fitted over the pot.
  5. Start the next machine measurement and wait until the results are printed.
  6. The mask is then partly released and re-secured with the right side of the mask placed and sealed over the pot.
  7. Start the measurement again and wait until the results are printed.
  8. Rip the receipt/paper from the machine and secure this to the mask or place inside the mask bag.

Stop testing:

  1. Unplug the tubes and seal the inlet as shown in the figure blow.
  2. Unload the plexi-glass and remove the masks.
  3. Unplug the particle counter.

Refilling the thermal print paper:

https://uk.rs-online.com/web/p/printer-paper/4804250/