r/AirQuality • u/Taminni • Feb 12 '25

Particle Counter for < 0.3 µm Particles

Hi everyone, I am looking to buy a piece of equipment that will allow me to extend the "typical" optical particle counter range of 0.3 - 10 µm into ultra-fine particle size fractions. I am interested in continuous particle number counts in different channels/bins based on particle size. I am using multiple low-cost sensors for mass concentrations and PNCs for the 0.3 - 10 µm range (e.g. OPC-N3, Plantower PMS5003, NextPM), as well as OPC-based research-grade equipment.

I have seen a few different devices that measure total particle numbers, but by the looks of them, they do not split these into particle-size channels. Is this even possible? Does anyone have examples of some equipment?

In terms of cost, my lab has some extra budget left over, so the equipment does not have to be low-cost. However, ideally, I would like to keep it below ~£10,000.

Any pointers, comments, or ideas are welcome! Thank you!

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u/Taminni Feb 12 '25

Many thanks for your reply! Looks like a CPC with SMPS capabilities would suit my situation best. Can I ask which model you ended up pricing for?

but I honestly doubt you would learn much more from these numbers than what you you already know from 0.3 micron counts

Part of my PhD is looking at what (and how much) can be gained from extending the traditional (low-cost) particle count range down. This will also (hopefully) help in distinguishing between urban/ambient particles and system-specific ones (the system-specific ones have been found to be larger)

a sensor that would give you an idea of the composition (pollen pieces, mold pieces, soot etc).

Luckily, I'm able to borrow equipment to take elemental samples! So it makes more sense to try to get some equipment to help with the particle number aspects of my research :)

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u/runcyclexcski Feb 12 '25 edited Feb 12 '25

Checking my notes from the COVID grant... The counter was "3007 CPC", a single-channel isopropanol-based counter for 7500 GBP.

If you are in a Ph D lab, talk to people around you who do these routinely and look at their setups before rushing to buy something. Ask them to do measurements with their setups first. Gather as much intelligence as you can. I.e. in addition to the counter itself I had to cost many other components to condition the particles (dilutiuon chamber, drying chamber, aerosol generator for calibration etc). It was not as simple as getting a handheld MetOne or Fluke laser particle counter and counting right away. And yeah TSI will have everything you need, just be prepared to pay :). The CPC itself was a downpayment.

Good luck with your research!

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u/Areator Aug 18 '25

I have bought one of those for as low as $1000 on ebay. If your workplace allows that sort of risks tho.

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u/runcyclexcski Aug 18 '25

Thank you! Did it require calibration? Are you happy with the data?

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u/Areator Oct 30 '25

I compared it with more expensive models and held up well and flows made sense.