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Dylos DC 1100-PRO particulate counter

PostPosted: Fri Sep 26, 2008 3:10 pm
by Wilberforce
I have just purchased the Dylos DC 1100-PRO particulate counter.
It measures particle counts down to 100 particles per cubic foot!
(~0.5 micron size, the upper tail of "efficient" combustion particle sizes)

It arrives next week. Will be posting again, once I start using it and
documenting air pollution crossing on to my property lines.

Pm counter

PostPosted: Fri Sep 26, 2008 4:33 pm
by Ernest Grolimund
How are you going to calibrate it?

PostPosted: Fri Sep 26, 2008 4:52 pm
by Wilberforce
They are calibrated at the factory for particle size/density.

My plan is to take comparative readings of:

A) a room where one cigarette has been smoked
B) a smoky nightclub
C) 2-3 feet away from my car exhaust pipe
D) a busy traffic intersection
E) on the freeway
F) a busy department store's back loading dock
G) downriver Detroit's industrial zone
H) finally, my own neighborhood's weekend smoky air

Comparisons like this, in graph form, tell the story. (There is
an optional computer hookup which can draw graphs in EXCEL.
This is objective empirical evidence of particulate air pollution.

PostPosted: Fri Sep 26, 2008 5:10 pm
by turning_blue
Excellent! I want one! Keep us updated. let us know if it's easy to use.

Pm counter

PostPosted: Fri Sep 26, 2008 5:20 pm
by Ernest Grolimund
You're a thinker for sure. All good ideas. I'm thinking of taking my Sears opacity meter to a state monitor and recording times when it changes readings. This is the only thing I can think of to calibrate it except asking the DEP to calibrate it or finding an environmental lab somewhere to do it which I cannot afford. Like the 1 cigarette in a room idea. Ott graphed that on CAR and you might get a rough calibration from that. Very interested in what you find. I may follow your example. I can afford $200 as a donation to science if I can convert particles to mcg/c.m.


PostPosted: Fri Sep 26, 2008 5:33 pm
by Ernest Grolimund
Calibrated for density? Density is mass per volume. Whatever the mass units and volume units are, I can convert to mcg/c.m., micrograms per cubic meter , turning blue. I want one too. You're a leader Woody.

PostPosted: Fri Sep 26, 2008 6:03 pm
by Wilberforce
Actually I meant "density" as being "particles per unit volume" (density is not the
right word to use.) In other words particle count per cubic foot of polluted air.

The actual "density" of the particles themselves are probably close to wood itself
(slightly less than water) but there may also be heavier salts present (fly ash)
which puts us right around 1 g/cm³. Knowing avg particle size, and avg particle
(let us call it specific gravity) we can calculate mass concentration. That is,
"30µg/m³" this can be directly compared against EPA standards. (I think Europe
and Australia use particle counts) Can we lobby the USEPA to change to counts?


PostPosted: Sat Sep 27, 2008 4:49 am
by Ernest Grolimund
Converting from partiles/c.m. to mcg/c.m. is a problem. There definetly are heavy air toxics clinging to the wood like particles and your ideas to convert are suspect. What does the company say? What does the EPA say? If Europe uses particle concentration and the U.S. uses density there should be some way to convert. If not, the EPA should figure this out and probably would if asked. Your local state DEP might be able to figure this out. Maybe I can ask my state? My state says portable monitors may be acceptable for hot spot mitigation but not ambient air determination. They insist on only $50,000 EPA approved monitors for that. Other questions are: What is the accuracy, plus or minus what? The lack of measurement capability below .5 microns does not seem to be a problem for us. It will make the measurements conservatively on the low side but not by much as I think of it. I'm going by memory of the particle size chart you found and posted.

The density of a particle would have to be very variable depending on water stuck to it and toxics that vary with air supply and temperature and maybe other things. How about comparing the particle count to european standards? Scientists appear to be thinking of particles as just the carbon flakes or charcoal like ash independently of air toxics which are thought of as seperate independant molecules of chemicals. Perhaps there are whole tables of conversion factors based on type of burning equipment. It is all too complicated for me. Not interested anymore unless an authority of some kind can make the measurements useful.

Do'nt give up on this idea. It could work out. It is what we all need: An affordable way to measure particulates. One other thing: particle counts would be pm10 not pm2.5. Pm2.5 would be a fraction of the pm10. Again very variable. The U.S. seems more advanced than Europe by having pm2.5 monitors. I think the DEP should buy some and loan them to people willing to pay for them if they break them or let their personnel use them. Cities could do likewise but are not interested in doing this kind of thing.

How about borrowing the CAR monitors? If one of us cannot buy one at $4,000, maybe 100 of us could at $40 per person. I would. Anybody else?

PostPosted: Thu Oct 02, 2008 10:38 am
by kaszeta
I have one of these, too.

I'm trying to see if I can put it in our clean room at work, where I have other (much more expensive and calibrated) instruments to check it's quality.

Like the other posters, I'd like to be able to come up with a justifiable conversion from particles/cf to ug/m^3, but this is going to take some work.

PostPosted: Thu Oct 02, 2008 11:56 am
by Wilberforce
I wonder if the EPA can help us out on this conversion.
When I find official documentation on this, I will post it.


PostPosted: Thu Oct 02, 2008 3:02 pm
by Ernest Grolimund
Good to have you on board Kazzy. Between you and woody, I'm hopeful the conversion rate will be found, if it can be. The EPA sounds like the best idea. Thanks.

PostPosted: Tue Oct 07, 2008 8:25 pm
by Wilberforce
The Dylos DC-1100 air quality monitor has arrived! It is very easy to use:
just plug it in and turn it on; it starts measuring particle counts right away.

On the back of the instrument is a chart:
"Air Quality Count 0.5 µm - Small Count Reading

3000+ = Very Poor
1050-3000= Poor
300-1050 = Fair
150-300 = Good
75-150 = Very Good
0-75 = Excellent

(multiply the number by 100 to obtain number of particles per cubic foot.
For example, if the display reads 150, there are 15,000 particles per cubic foot.

Some particulate readings from the last three days in and around my home:

____________Fine (0.5µ)___Coarse(2.5µ)
indoors frying......3000.................400
outdoors wood*..2800..................110
outdoors yel.......1800...................15
outdoors grn........500...................25
filtered room**.....75....................10

*outdoors wood: there was a slightly-noticeable wood smoke smell in the air
** small closed room with continuously-running inexpensive HEPA air cleaner.
'outdoors yel, grn' means readings taken on code yellow or code green days.
Normally "coarse" applies to 10µ size, here, "coarse" is for comparison only.

Note: 0.5µ = 500nm, ~one wavelength of visible light. (PM 0.5)
"Coarse" = visible particles> (PM2.5)

PostPosted: Wed Oct 08, 2008 8:35 pm
I too would like to be able to convert particulate measurements from one of these laser particulate monitors into the mass/volume standard. I've got months worth of continuous particulate measurements I've been hoping someday to convert. (i.e. #particles/liter .. 10., 2.5, 1.0, etc. sizes) (Measurements are outdoors near a wood fired boiler/co-generator power plant in my neighborhood). The handheld meter/datalogger I used seems accurate and costs over $4000... but getting meaningful numerical data from it in mass of particulates counted is daunting.

Will any low-cost meters like the TSI SidePak really produce readings that can be compared to American standards?

PostPosted: Mon Oct 13, 2008 1:22 am
by Wilberforce
HI there! Here is a free booklet for D/L.
I am writing an essay pertaining to your question of particle mass/counts.
But I must do more research on this. There are many unknowns to deal with.

Basic Guide to Particle Counting
Particle Counters, Microbial Air Samplers, and Molecular Contamination Monitors
Information Spotlight: (UPDATED: Basic Guide to Particle Counting)
(fill in your name, email, etc in order to download the free PDF article)

PostPosted: Fri Oct 17, 2008 9:57 pm
by Wilberforce
Here are some interesting recent particle counts taken on the Dylos 1100PRO

Outdoor, 'green' day..............270-350.................10-40
Lawn mower exhaust................700.....................200
Indoor, tobacco smokers........13,500.....................200
Neighbor 'smoker' BBQ...........13,000...................1,000
Badly-burned toast...............34,000..................27,000

Lawnmower exhaust: reading taken 1m from exhaust pipe,
right in the direct exhaust stream
Neighbor's smoker BBQ: calm day, reading taken at 85m distance.
Indoor, tobacco smokers: small house, smokers had left earlier.

The lawn mower is new, with no cat converter. I was no less than
astounded at the low counts, but even more astounded at the comparison
with the back-yard BBQ. The foul odor could be smelled at a radius of at
least 500 feet in every direction. I walked by the house and saw the smoker.
Thick smoke was rolling out of the thing. You actually gonna eat that?