Particles are all the physical little pieces of stuff floating around in the air. Sometimes they can be visible to the naked eye (like a large floating piece of dust or pollen), but, most of the time, when we’re talking about particles, we’re talking about the ones that are too small to see. But we’ll get to sizing in just a minute.

In the era of COVID-19, the general public has been paying a lot more attention to the cleanliness of their air. There’s been a lot of discussions around what masks will and won’t be effective against the virus in the air due to the size of the particle. (As a side note, if you want a mask that’ll keep you breathing cleanroom-grade air, check out Flitr’s N-95.)

But here in the particle counting and cleanroom industries, particles are our specialty. We monitor state of the art systems to keep particles out of cleanrooms so they can continue to manufacture goods without contamination.

So what happens if we don’t pay attention to particles?

The Consequences of Not Paying Attention To Particles

Depending on the industry you’re in, not paying enough attention to the size of particles in your cleanroom can be catastrophic.

In the manufacturing of nanotechnology, particles can stop products from working or cause malfunctions. This can lead to forced recalls or negative reviews and a bad reputation from equipment constantly going awry.

Other industries that involve large amounts of glass, like photography and lens construction, also need to closely monitor particles. If these products are marred by particles, the images will be distorted.

But in other industries, particles can throw off entire scientific pursuits or put lives at risk.

For instance, scientists were so excited when samples from other planets showed microscopic signs of life. But later studies revealed that poor collection and handling contaminated the samples and there were no signs of life.

While that was an embarrassing gaffe for the scientists, no lives were truly in danger. But in industries such as pharmaceuticals, medical equipment manufacturing, space travel, and weapons application, contamination can have catastrophic effects.

Anywhere in the medical field, contamination can lead to infection. This results in lawsuits, licenses being threatened, and potential loss of life. This is why it’s critical for practitioners to trust their manufacturers - and manufacturers to be trustworthy. It’s critically important to maintain FDA standards to continue manufacturing, as well.

In weapons technology and space travel, users are actively putting themselves in dangerous situations where all pieces of equipment must be performing perfectly.

Particle Sizing

We usually measure particles in microns - or one-millionth of a meter. This can also be called a micrometer, but the industry standard is to call it a micron. This is a suitable size to measure most particles, but there is a smaller unit of measurement.

The nanometer is one-thousandth the size of a micron and one-billionth the size of a meter. Particles that are a nanometer are substantially smaller than micron particles.

So how small is a micron?

A single micron is way too small to be seen with the human eye. But we can see a human hair, which is around 100 microns. And a salt grain measures 60 microns.

But pollen often measures at 15 microns - and we know that we can feel pollen in the air and in our sinuses. But we can’t necessarily always see it. That’s a true measure of how the air quality can impact us without us being able to see what’s causing the irritation.

At an even smaller measurement, bacteria measures 5 microns and viruses measure 0.1 microns. The COVID-19 virus usually measures between 0.06 and 0.14 microns.

We mainly use two types of filters to stop particles of that size: HEPA and ULPA filters. HEPA filters are the most common and their Most Penetrating Particle Size is 0.3 microns, which means they are certified to catch particles of that size. But they can catch smaller particles.

ULPA filters are finer. Their Most Penetrating Particle Size is 0.12 microns, so they are used in a lot of cleanrooms that have higher cleanliness needs.

How We Detect & Size Particles

To detect and size particles in a cleanroom, we use a particle counter. Here at Lighthouse Worldwide Solution, we take a lot of pride as the world’s leader in particle counting technology. So we take particle counting pretty seriously.

Particle counters contain a laser sensor block that detects and sizes particles. This block contains:

1. Sensor housing
2. Laser diode
3. Sample inlet
4. Sample exhaust
5. Sample view volume (where particles pass through the laser and scatter light)
6. Sensor cavity & optics
7. Photodetector

Particle counters use a science called light scattering to detect and size the particles. Essentially, a pump is used to create a vacuum in the particle counter that sucks air in from the cleanroom. The air is sent through a laser to detect the particles.

As the particles pass through the highly focused laser, light is scattered. The larger the particle, the more light is scattered. The inverse is true, as well. The smaller the particle, the less light is reflected.

The photodetector is used to quantify how much light is scattered. Through that quantification, the particle counter can tell us what size the particle is, as well as how many particles are passing through the laser.

This gives us a good idea of how clean the cleanroom really is - and allows us to certify it.

How To Find The Right Particle Counter For Your Cleanroom

Properly certified, calibrated, and maintained particle counters are the foundation of a functioning cleanroom. If you need a certified cleanroom, you will need a highly-functioning, calibrated particle counter.

So how do you know which one is right for you?

This depends on the size and function of your cleanroom, but we can help you through this process.

today to make sure your particle counter needs are being met.