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PostPosted: Mon Oct 27, 2008 12:25 pm
by Wilberforce
Here are the lowest outdoor readings yet 90(ultrafine) and 8(coarse) taken on my Dylos
particle counter. This is the result of last night's cold front, which swept down from Canada.
My Canadian friends: the good, clean air is an import which is greatly appreciated here!

PostPosted: Wed Nov 19, 2008 8:15 am
by turning_blue
Woodnyet, where did you purchase this and how much is it?

Nevermind, I see the link.

PostPosted: Wed Dec 03, 2008 3:11 pm
by turning_blue
I received my Dylos DC-1100 air quality monitor. I have been experimenting with the unit taking measurements in the morning and in the evening. So far the evening air inside my home has measured fair to poor. (According to Woodnyet's post/chart below). The evening highs have been 2,250 on the second floor, 2,000 on third floor and 1,700 one the first floor. The morning highs were 750 on the second floor, 450 on the third floor.

The evening readings have been higher. I'm not sure why. Could it be that there is more burning or that pollution is trapped and more concentrated with the temperature inversions?

Readings were taken around 9:00 pm and 10:00 am.

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

PostPosted: Wed Dec 03, 2008 6:33 pm
by Wilberforce
My computer room has a cheap air cleaner running at low speed, continously.
The particle counter readings in that room are consistently about ~1/10 of
whatever the outdoor reading is. For example, if the outdoor reading is in
the 1,000 range, then the indoor reading will be in the 100 range.

Last night, the indoor reading shot up to >600. The corresponding outdoor
reading was over 10,000! There was a smell of burning plastic in the wind.
Since the wind was out of the SW, I got in my car and headed in that general
direction to find the source. Turns out that three miles from my house, I was
still a few miles downwind of the stink, of what may have been burning wire
insulation. Was this a house fire, or was some jackass burning the plastic
insulation off of a pile of stolen copper wire? They are doing that here in town.

The readings suggest that, even with closed windows, a home interior particle
count correlates linearly with outdoor particle counts. (many, many readings
have been taken like this, not just two)

Dylos teaching us all

PostPosted: Thu Dec 04, 2008 8:42 am
by Ernest Grolimund
Great and simple low cost experiments. Now you are really learning. Your results correlate with my opacity meters except sometimes I got opacity readings showing very unhealthy odors while the dust or particles were in the healthy range. With the IQ Air air cleaner I have always had healthy readings inside.

My canary in the coal mine is not acting up either. That's my asthmatic daughter.

The DEP says pm is lowest at night. There is a morning peak corresponding to rush hour traffic and wood burning to take the chill out of the air. Then it drops quickly all day but picks up at night with rush hour traffic and more wood burning. Even though the oil furnaces are going full in the night, the air pollution goes down to a minimum.

An eddy current builds on the side of the house where the wind hits and this creates positive pressure causing infiltration. House levels are typically half outside air levels but do not know what eddy current levels are.

The inside air is not cleared by the wind so it can stay high for hours. I am basically doing the same thing as woody with different equipment. We have to protect ourselves. For me, it also lowers the anxiety!

A good research project would be to contact the UN and get international standards for waht is good, unhealthy and very unhealthy and find out where asthma begins to be affected, when it causes doctor visits and more meds and where it causes attacks causing hospitalizations. For pm2.5 these levels are 18, 24, 30 mcg/cubic meter. Get enough good information and you may be able to use the information in court or to keep you out of court. The Maine legislature was impressed that I was measuring the pollution when no one else was and it helped pass the outdoor wood boiler bill though it was flawed in my opinion and the opinion of the Am Lung Assn.

I am sure many people will be drawn to this post. Good work.


PostPosted: Thu Dec 04, 2008 9:08 am
by Ernest Grolimund
Temperature inversions amplify pm pollution per DEP. Calm wind inversions amplify pm pollution too per Dr. Brown and the ALA. I am most worried about the calm wind inversions which happen once per week per Brown or more. Valleys or low lying areas or depressions or pockets also decrease wind and increase pollution concentration in my experience and from DEP conversations.

Do not forget that wood smoke is a double whammey. It is pm and toxics. Therefor, it is more toxic than just ambient pm according to the Maine DEP. Therefor, standards for ambient pm do "NOT" apply. It takes a higher amount of ambient pm to cause health effects per the Maine DEP from conversations. Sorry guys, I am a talker not a computer researcher so I can't always get references but you can check me by calling authorities. Wood smoke is the #1 air toxic according to the Maine DEP and diesel is #2. This means it is wrong for lawyers and other people to say you must put up with pm2.5 at 35mcg/cubic meter for 24 hr. The Brown standards from hospitals can then be invoked for wood smoke pm and they are 30 mcg for 3-4 hrs causing asthma and heart attacks, and yes for point of emphasis, this can "KILL". Brown says it. The ALA agrees. Hospitals say it and CAR says it. 3 high credible sources. The Maine Toxicologist said to me that Brown is a good scientist and he accepts his scientific statements. The head of the DEP Air Bureau in Maine agrees that Brown is a very credible source recognized by the EPA although it may be a while before his work leads to lower standards. Government is led by businessmen and non scientific people.

My conversations are not writings but they can be a source of inspiration for you guys to write letters and get this in writing. Courts prefer oral testimony from experts that can be cross examined. Wish I was an expert but I am not so a quote of me is useless, except as a victim telling smoke stories. There are so many of them here that a judge or any sane person would have to be influenced.

PostPosted: Mon Mar 09, 2009 12:24 am
by Wilberforce
Gradko DC1100 (I think this is the same unit as Dylos DC1100, but under a different name [in U.K.]) ... itor/2957/


These folks are woodworkers concerned for their health. They are considering a "group-buy-discount,"
which is not a bad idea for us to consider doing here also. Read on:

Dylos Air Quality Monitor Group Buy (Canadian Woodworking Forum) ... 70&t=25360


Here are some readings I've been taking over the last few months. All have been made in conditions of
<80% relative humidity. (In saturated air, there is an abundance of water vapor nanoparticles, making
readings too high.) Low humidity contains far fewer vapor particles. The readings were taken at the
same location, when noticeable odor was present. (Not corrected for baseline.) Wind disperses particles
much better than stagnant air can, as suggested by the much-higher "calm" readings. These readings
are a running average of several dozen individual observations.

A reading of 3000 on the instrument is considered very poor air quality (orange zone.) "3000" means
3000 particles per one-hundredth of a cubic foot, or 300,000 particles per cubic foot, or 10.6 million
particles per cubic meter.

Typical neighborhood wood smoke readings taken on the DC1100 particle counter:

                                                    fine(0.5µm)              coarse(2.5µm)

                     windy day                       600                             50
                     calm day                   2000-9000                     100-700

Conversion Info.

PostPosted: Sat May 02, 2009 9:43 am
by Ernest Grolimund
Was browsing through books at the local DEP, and came across a conversion factor. From Norm Anderson, MS Public Health, Am Lung Scientist. "To convert from mcg/m3 to ppm, multiply by .023/M where M is the mol. Wt." How you figure out the mol wt is a problem too but Woodnyet has been picking up ave diam and from that you can get volume of a sphere, and if you can get density maybe you can calc wt. I am not really talking about a molecule though. Pm is a solid with molecules adhering together and toxic gases stuck to it. There must be a way to convert. United Nations? Dylos? EPA?

Re: Dylos DC 1100-PRO particulate counter

PostPosted: Sat Oct 24, 2009 4:53 am
by swiper
I am quite interested in buying a Dylos from the States while our dollar is almost near 1:1.
But...will it do what i want, I don't know??
Because our NEPM standard is 24 hour average weighed method, I sent an email to Dylos and they said it isn't possible to convert it's output to ug/m3.
So I then emailed an air guy and this is what he said:
Yes, in a sense, at least approximately. You can do the sums if you assume that smoke particles have a similar density to water, and adopt a nominal diameter say of 0.5 um (very nominal). This gives you a mass (from the volume of a sphere and the known density) for each particle and hence you can go to total mass per m^3.

To really do it though you need to characterise the aerosol in question.

(Were you asking about smoke or dust?)

The instruments we use sort of do this calculation – they count particles, they don’t weigh them. What we do is to calibrate them against the gravimetric instruments and say ‘when we measured X particles in total on this day with this instrument we obtained Y ug/m^3 on the gravimetric’, so we know if we measured 2X particles in a day we should be near 2Y ug/m^3 gravimetrically. Obviously we do the calibration over a number of days and cover a range of ug/m^3 to check for a linear response.

I don't have a gravimetric instrument to calibrate against.

Perhaps somebody might be kind enough to help me with the workings (formula) I actually have to use if you think this method will work.

Re: Dylos DC 1100-PRO particulate counter

PostPosted: Sat Oct 24, 2009 8:58 am
by Wilberforce
I had the same idea, calculate particle diameter to volume, but using a hybrid
(average of) sphere and cube (a cube with a given diam has about 1.8 times the
volume of a sphere of similar diameter, hence weighs 1.8 times more.)

This is because some of the (liquid phase) particles might be spherical, while
the (solid phase) particles may be more cubical. I'm thinking of dividing into
these two categories in order to estimate more accurately.

Lastly, I feel that particle counters are a better way to measure instantaneous
changes in pollution amounts in ambient air shed than particle weight, (which
is an "amount over time" technique. Also, I feel that mass measurements are more
suited for measuring the direct output of a smokestack or vehicle exhaust pipe
than counts are, because of the overwhelming number of individual particles present.

Re: Dylos DC 1100-PRO particulate counter

PostPosted: Sun Oct 25, 2009 4:18 am
by swiper
Thanks Woodnyet.
Now I certainly don't want to get off the track with weights and counts, but while I ponder all this there are some other questions i put to Dylos that were not answered.....
Dylos says i will have to buy an International wall adapter to convert to our 240V ac @ $42.87, and Australia also has to have all electric appliances RoHS compliant which is also an additional cost of $35.00.
Now i don't know what the power requirements are for the Dylos. Does it come with rechargeable batteries, does it have its own mains voltage plug pack, if so what voltage and current?
Perhaps i could supply my own mains plugpack so i don't need the $42 converter and if i am then only buying a low voltage dc instrument then I mightn't need it to be RoHS compliant.

I have asked for a spec sheet, didn't get that either.

Re: Dylos DC 1100-PRO particulate counter

PostPosted: Sun Oct 25, 2009 5:56 pm
by Wilberforce
Probably the reason it is difficult to directly convert (by calculation) particle count into particle
weight concentration is the range of particle sizes. 0-2.5 µm. We would need to use the integral:

   d=2.5  µm
d dx
   d=0  µm

or the volume equivalent, in order to calculate all size ranges.

By the way, the Dylos unit is intended for indoor use and is not powered by batteries,
therefore not portable. You might try this unit instead, which measures mass (I think)

The UCB particle monitor

Re: Dylos DC 1100-PRO particulate counter

PostPosted: Mon Oct 26, 2009 5:37 am
by swiper
Mains only, that answers my questions about certification requirements.

I checked out the site for the UCB-PM at ... 9&Itemid=1
It's a tad more expensive, but I have written to them asking a few unknowns, so we will see.
Thanks again

Re: Dylos DC 1100-PRO particulate counter

PostPosted: Tue Oct 27, 2009 3:41 am
by swiper
This was the reply:
Our device is sold through Berkeley Air Monitoring Group, but does not have the sensitivity for your situation, I am afraid. We are working on a more sensitive version, however, and may have something available next year. See

Re: Dylos DC 1100-PRO particulate counter

PostPosted: Tue Oct 27, 2009 5:57 pm
by Wilberforce
I would rather use the dylos unit anyway, because it provides instantaneous readings, updated several times per second. :D