Air quality meter, what make model, what do they cost?

[Randall J Cox]

Want to get an air quality meter for my shop to see the particle count and how good or bad my system is. What makes and models are recommended? Don' want to spend lots of $ if I don't have to (like anybody I guess). Tx. Randy

[Frank Pratt]

This is a really decent, inexpensive one:

https://www.banggood.com/PM1_0-PM2_5...r_warehouse=CN

They have another model for a few bucks more that can be connected to a computer for data logging, if that's something you want. You do have to provide your own USB power supply. I have a USB battery velcroed to the back of mine so I can move it around the shop to keep track of what the air's like where I'm working.

[Alan Lightstone]

I have the same one. Not sure how accurate it is (may be very accurate, I just don't know), but it's nice visually. I had a friend buy one who was getting pounded by the air from the wildfires. Readings were scary.

Frank's idea about the USB battery is a very good one.

They will non-stop spam you after purchase though...

[Jim Becker]

I also bought the unit that Frank mentions and it's useful for showing relative air quality. I have no idea if it's "accurate" in a pure scientific way, but it serves a good visual purpose with both the numbers and the color coding. If things start to ramp up, I know that I have to deal with it. It's in a visible place and actually uses my communication system UPS for power as it has USB power ports on it for convenience.

BTW, once you get your order if you buy it, you'll need to be proactive to stop the marketing emails. Companies like Bangood are very agressive marketers.

[Frank Pratt]

Yes, they do love to send the promo emails. I won't call them spam, because I consented to them when I made the purchase & I can always opt out.

WRT accuracy, I've read other users' experience with testing the accuracy & it seems like they are not too bad. My use methodology is to look at the counts when I first go into my shop to get a baseline & then use it as a relative measurement. The baseline count in the shop is always much lower than in the house, and it has a top end 3M electronic filter. When working in the shop, I can usually keep counts as low, or lower than in the house.

[Jim Becker]

That's how I do it, too, Frank...check the reading before I start doing stuff and keep track relative to where it moves to as I'm working. (assuming I remember to do so...but that's a separate issue. LOL)

[Frank Pratt]

(assuming I remember to do so...but that's a separate issue. LOL)

and there's the rub...

[John K Jordan]

Want to get an air quality meter for my shop to see the particle count and how good or bad my system is. What makes and models are recommended? Don' want to spend lots of $ if I don't have to (like anybody I guess). Tx. Randy

I've had the Dylos for years (bought in 2012), recommended by Bill Pentz, also others here and on other forums use it. Not cheap.
https://www.amazon.com/gp/product/B004AWEG0Y

The one discussed here is so inexpensive that unless someone else says they've already done it I think I get one and compare it to the Dylos. Might be interesting.

JKJ

EDIT: Hmmm. Tried to order and pay with PayPal and gave up waiting after about 5 minutes. Site locked up?

[Alan Lightstone]

I've had the Dylos for years (bought in 2012), recommended by Bill Pentz, also others here and on other forums use it. Not cheap.
https://www.amazon.com/gp/product/B004AWEG0Y

The one discussed here is so inexpensive that unless someone else says they've already done it I think I get one and compare it to the Dylos. Might be interesting.

JKJ

EDIT: Hmmm. Tried to order and pay with PayPal and gave up waiting after about 5 minutes. Site locked up?

I looked at the two of them side-by-side when I first bought mine, but didn't know the conversion formula for the particle count to AQI so I never really did that. One of these days I'll get around to it.

[Scott Winners]

the conversion formula for the particle count to AQI so I never really did that. One of these days I'll get around to it.

I think I got this one. EPA regulates (outdoor) air quality based on particle counts. I am in a city that gets regularly spanked on our PM 2.5 counts. The PM 2.5 count to EPA regulated Air Quality Index (AQI) in repeated on this page:

http://data.fnsb.us/airquality/AQNearRealTime , FWIW I live kinda near the "oa" in Broadmoor towards the left side of the 'rectangle of death' aka non attainment area.

There are probably similar EPA regs for PM10 and so on, outdoor PM2.5 is the thing EPA is spending tax dollars on here.

[Alan Lightstone]

David:

I had previously used the Dylos formula for calculating AQI from their meter (at your suggestion in our previous thread). This is the explanation on Bill Pentz's website:
http://billpentz.com/woodworking/cyclone/dylos.php

In essence, it is PM 2.5 = (Small Particles - Large Particles) /100

Now the units may be wrong here, and David please correct me if that is the case. I believe this gives the number in mcg/m3 which is the typical units for PM 2.5.

Alan

The next time I run my wide belt, I'll put both meters next to each other, and look at the readings.

[David L Morse]

David:

I had previously used the Dylos formula for calculating AQI from their meter (at your suggestion in our previous thread). This is the explanation on Bill Pentz's website:
http://billpentz.com/woodworking/cyclone/dylos.php

In essence, it is PM 2.5 = (Small Particles - Large Particles) /100

Now the units may be wrong here, and David please correct me if that is the case. I believe this gives the number in mcg/m3 which is the typical units for PM 2.5.

Alan

The next time I run my wide belt, I'll put both meters next to each other, and look at the readings.

Yes, that formula provides a rough estimate of PM2.5 and the units are indeed mictogram per cubic meter. If you want to trudge through the math the assumptions are a particle diameter of 1.5 micron and density of 1.6 g/ml.

Obviously there's a lot of room for uncertainty when you have to assume an average particle diameter for a distribution that ranges over a 5:1 range. That's actually a 125:1 range for the mass per particle. Size distribution varies a lot for different materials and generating processes as well as distance from the source.

For more details on using particle counts to estimate PM levels see this paper.

[Frank Pratt]

Yes, that formula provides a rough estimate of PM2.5 and the units are indeed mictogram per cubic meter. If you want to trudge through the math the assumptions are a particle diameter of 1.5 micron and density of 1.6 g/ml.

Obviously there's a lot of room for uncertainty when you have to assume an average particle diameter for a distribution that ranges over a 5:1 range. That's actually a 125:1 range for the mass per particle. Size distribution varies a lot for different materials and generating processes as well as distance from the source.

For more details on using particle counts to estimate PM levels see this paper.

There's a little light reading For now I'll stick to my simple relative method of monitoring air quality.

Thanks for offering those explanations David. It's nice that you have put your brain to work so that some of the rest of us don't have to.

[John K Jordan]

Thanks for offering those explanations David. It's nice that you have put your brain to work so that some of the rest of us don't have to.

David is my new hero.

JKJ

[Alan Lightstone]

My old hero.