Dust sensors acting as pollen sensors

Hi guys I was wondering if you could help me with a question I have.

I am looking to create an indoor 'environment' monitor that monitors all sorts of conditions in the room such as temperature and humidity but also dust particles and pollen to monitor allergies.

So I have think I have decided on this sensor to monitor dust: https://www.sparkfun.com/products/9689

As it does require a resistor to heat up in order to detect the dust particles which is an advantage over it's competitors.

I am struggling to find a sensor though that detects pollen. Any suggestions would be helpful. :)

Although as I was reading around I thought I read somewhere (can't seem to find it again) that either this dust sensor or similar ones also sense pollen. This is because they sense particles in the air and both dust and pollen are particles.

I'm not sure how to distinguish whether this sensor is sensing dust or sensing pollen. I'm not sure if it was this sensor or a different one that can tell the size of the particle and this is how is knows whether is is a pollen or a dust particle. I do believe it was the one linked above though.

I would like this project to be able to know levels of both pollen and dust.

So in summary: Does anyone know a sensor that detects pollen? Does anyone know whether the above sensor also senses pollen? If so how can you distinguish between dust and pollen

Thanks in advance

I think that is not possible. A nose can detect pollen long before any dust detector would. To measure the pollen, pull air through a filter, and after 24 hours, investigate the filter in a laboratory.

This is a patent : http://www.google.com/patents/US20040066513 The patent is about to distinguishing pollen from dust. Honestly, I doubt of that will work.

My understanding of the above dust sensor is that it is actually a particulate sensor rather than exclusively a dust sensor.

So does that mean it will sense both pollen and dust? It just won't know which is which.

Have you googled "pollen sensor"? Lots of hits.

Yea I have but when I do I get results such as the dust sensor linked above as well as the PS2 Pollen sensor by a company that also produces a dust sensor which costs $2,200.

If you are able to link to any of the results you have that would be helpful all I get is the same range of particle and dust sensors nothing new.

If you want a cheap solution, you are out of luck. It is [u]very[/u] difficult to automatically and reliably distinguish pollen from other small particles.

One sensor manufacturer mentions use of light polarization, which makes sense as many biological compounds affect the polarization of light. Polarization changes are hard to detect on a small scale, which explains why the sensors are so expensive.

For many decades, people have looked at particles under a microscope. Pollen grains are very distinctive in their appearance and can simply be counted.

OK thank you for your help. Is my understanding correct when I think that the above sensor is actually a particle sensor and will sense both dust and pollen? So if the amount of dust in the air remained the same but the pollen count went up I would see an increase in the particles detected by the sensor?

The sensor you linked in the original post is reflective, so any particle above a minimum size will be detected.

http://www.shinyei.co.jp/stc/eng/optical/main_poln.html

this could serve the purpose IMO. I don't know if it can be interfaced to Arduino.