Stuart Longland (VK4MSL)<p>So, the other day I noticed a strap on my Honeywell RU6500 <a href="https://mastodon.longlandclan.id.au/tags/FullFaceElastomeric" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>FullFaceElastomeric</span></a> had broken… this is one I was keeping around for parts, so not a big issue… but the thought of the same fate meeting my current one worried me a bit.</p><p>Looked around, found a new Sundström SR200 going for a bargain price (AU$250… normally they are >$550)… beauty. It's on its way south from Mt. Isa.</p><p>Today I ordered some filters (from a local supplier here in Brisbane), mainly some <a href="https://mastodon.longlandclan.id.au/tags/P3" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>P3</span></a> filters (my main concern is <a href="https://mastodon.longlandclan.id.au/tags/bushfire" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>bushfire</span></a> smoke and <a href="https://mastodon.longlandclan.id.au/tags/COVID19" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>COVID19</span></a>)… I happened to notice this little chart for the SR-510 particular filters.</p><p><a href="https://www.allensindustrial.com.au/documents/Sundstrom%20SR510%20Brochure.pdf" rel="nofollow noopener" translate="no" target="_blank"><span class="invisible">https://www.</span><span class="ellipsis">allensindustrial.com.au/docume</span><span class="invisible">nts/Sundstrom%20SR510%20Brochure.pdf</span></a></p><p>Classes:<br>- P1: 80% | up to 20% leakage | Protect against Dry and Wet particles _except_ aerosols, carcinogens, radioactive particles, bacteria, *viruses*, spores or biochemicals such as enzymes or hormones<br>- P2: 94% | up to 6% leakage | Protect against Dry and Wet particles _except_ *viruses*, spores or biochemicals such as enzymes or hormones<br>- P3: 99.95% | <0.05% leakage | Protect against Dry and wet particles (all types)</p><p>It was the exceptions for "viruses" in the <a href="https://mastodon.longlandclan.id.au/tags/P2" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>P2</span></a> and <a href="https://mastodon.longlandclan.id.au/tags/P1" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>P1</span></a> filters that surprised me. I thought <a href="https://mastodon.longlandclan.id.au/tags/P2" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>P2</span></a> was more or less equivalent to <a href="https://mastodon.longlandclan.id.au/tags/N95" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>N95</span></a> and <a href="https://mastodon.longlandclan.id.au/tags/KF94" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>KF94</span></a>. (P3 being equivalent to <a href="https://mastodon.longlandclan.id.au/tags/N100" class="mention hashtag" rel="nofollow noopener" target="_blank">#<span>N100</span></a>) I hear people singing the praises of N95s with regards to COVID-19, and definitely it beats many common alternatives, but this has me scratching my head.</p><p>The SR-510 is a P3 filter, so no biggie… but I thought P2s were up to the task.</p><p><span class="h-card" translate="no"><a href="https://a.gup.pe/u/auscovid19" class="u-url mention" rel="nofollow noopener" target="_blank">@<span>auscovid19</span></a></span></p>