how good is the Dylos DC1100 air quality monitor?

[pmeunier]

These particle counters are aimed at home owners:
http://www.dylosproducts.com/learnabout.html

It has two readings, one for "small particles" > 1 um and another for "large particles" ("from approximately 5um and up"). It's obviously too coarse for professionals, but it might be useful for a home owner wondering what makes a difference. I just wonder about its reliability and durability; will it stop working after a year? Two? Five? Will it produce wildly variable counts, or reproducible ones? Has anyone used it? Does it have annoying quirks or notable weaknesses?

Thanks...

[mbarson]

Ya get what ya pay for. Looks like a gimmick to me.

[lpc_engineer]

I am the designer of the DC1100 so I don't claim to be impartial, but this instrument is no gimmick - it is a true laser particle counter! I spent 13 years designing particle counters for clean room use which cost from 8 to 16 thousand dollars. I targeted the DC1100 primarily at the home user who wants to know their indoor air quality and when it is time to change filters, turn on their purifiers, etc. However, HVAC professionals are also finding it useful as a tool. Not only for their own diagnosis, but to demonstrate to their customers the effectiveness of their work. Some also leave it in homes to gather data for review during follow up visits.

To address some of your concerns ...

As for reliability - we've only been marketing this product for about a month and haven't had any fail yet. The main problem with laser particle counters is the laser dying. Lasers just do that over time. I've done accellerated life tests for several months without failure so I would expect the laser to last for years. In any case, our repair charges are easy on the wallet - $35 flat fee. Remember, your $4500 Fluke will also need annual calibrations which will run hundreds of dollars.

The 1um lower detection range - we felt this was adequate for the home user, but HVAC professionals are more demanding. We have units with 0.5um detection limits for a small additional charge upon request. We just didn't feel the home owner would care enough to pay extra.

I am not saying the DC1100 is a better tool than the Fluke. The Fluke has a lower detection limit, is more rugged, and is battery operated (the DC1100 must plug in). But for many uses it will work just as well for a tiny fraction of the cost. The DC1100 actually is better in some ways as it has large bright numbers on the display which the contractor and the client can easily view while the unit is sitting on the table. The DC1100 also stores data so you can go back and look at the daily averages over an entire month or hourly averages over the past day, etc.

The DC1100 is no gimmick, it's the real deal!

[pmeunier]

Very interesting, thanks. I'll want the 0.5um detection limit, that was bothering me a little. I think I'll order one the next time I'll indulge myself. Heck it's cheaper than a vacation trip and I'll probably have more fun with it than dealing with air travel and hotels. (and the allergies due to their carpets and general lack of dehumidification )

Who dies with the most toys wins?

Seriously, I think it will help me to know for sure if the filters I have are doing their job, if the tinkering I do helps any, and whether I should stay indoors or if it's a good time to go for a walk.

[mbarson]

lpc_engineer, please understand the most of us have seen things advertised for a very low price that fail to meet our expectations when used. Your product may be fine but I am always skeptical when I see extremely low prices. From a professional point I am always interested in accuracy. What is the accuracy of this unit. If it is fairly reliable I could see using one to log data at a customers house where you would not want to leave your Fluke unattended.

pmeunier. When you get your unit please post a review.

[lpc_engineer]

pmneunier, thank you for your comments. The DC1100 will do all those things you mentioned.

mbarson, accuracy is not normally specified for particle counters as it would be for say a volt meter. It is not unusual to see two $8000 particle counters disagreeing by 30% or so, especially from different manufacturers. A major reason for this is that units are calibrated with standard particles which are uniform, round, plastic spheres, but in the real world they measure irregular shaped chunks of whatever happens to be floating in the air. There is a JIS calibration standard, but it does not eliminate these issues. Fluke claims to do a calibration which at least partially adheres to JIS. I don't know what Fluke charges, but I'd say $450 is in the ballpark for this kind of cal. To keep the price of the DC1100 down to $149 I must use a proprietary calibration method. Overall the results are good and the readings on my units will pretty much track the Fluke or other counter's readings.

[breathe easy]

lpc
It never ceases to amaze me about the people who participate in this site.

I received a mailing on your device and was skeptical and tossed it. After reading your posts I would like to take another look at it.

Please contact us through our website.

[pmeunier]

lpc_engineer,

Let's say I managed to get very low counts somehow, perhaps by having a good HEPA filter running on the highest speed in a closed room. Almost every instrument gives a background noise count even when there's nothing to detect. In a situation where the count is low, that background noise count becomes significant. With your unit, is it possible to estimate or measure that background noise count so that I can subtract it from the readings?

[lpc_engineer]

The DC1100 reads out in particles per cubic foot divided by 100. So, if the DC1100 reads "1" that means there are 100 particles per cubic foot. You can easily get the DC1100 to zero count by putting filter material directly over the air inlet and sealing the edges with tape. By the way, those spurious counts you are asking about are sometimes called "dark counts" in the industry. Some particle counter manufacturers simply subtract off so many counts per minute to correct for this. The DC1100 by virtue of its design does not need any dark count correction. So, if you wait long enough you may be able to get the counts down to zero in a closed room. One of my customers actually tried this successfully, but as soon as any movement occurred in the room counts started registering. A well-filtered room might read 20 or so when the outside ambient reads 500. Another customer who was using very aggressive filtering and even some very basic clean room construction techniques was able to get consistent readings below 10.

www.dylosproducts.com

[genesis]

What is the particale size range ? Might be intrested if its 2.5 -.01

[lpc_engineer]

The Dylos DC1100 gives 2 readings .... small particles ( 1 micron and up) and large particles (5 microns and up). The readings are given as concentrations of particles/.01 cubic foot. That is, a reading of 2 means 200 particles per cubic foot. We also can calibrate for 0.5 micron instead of 1 micron - just ask, it's an additional $50.

[midhvac]

So what's the deal on the lifespan of the laser?

Is it the number of hours it's actually in use, or is the time it's not in use also a factor?

[lpc_engineer]

Generally a laser diode will slowly degrade while it is on. Its shelf life while off is usually much longer. Higher temperatures and output power of the laser accelerate this process. Diode lasers have tiny mirrors on their ends and the degradation of these mirrors is a major failure mode. As the laser ages it will draw more current to keep its power output up until it finally burns itself out. The laser on the DC1100 is relatively low power and has performed well in life tests so I predict a long life. It can also be placed into "monitor mode" where it will sample periodically, turning the laser off between samples, which would further extend the life.

[Kevin O'Neill]

I have one ordered. We should get it Tuesday. We are also going to borrow an Air Advice and check them against each other. We have someone who called us with allergy problems, we will see what we find out with these two instruments. I already have temperature and RH data loggers.

I will post after I have some solid data.

[Kevin O'Neill]

Ours just came in. The data logging is displayed on the 2 line screen. There is no way to hook it to a computer.

I will run it in my office at my shop for a day to see how it does, then I will take it home and see what I get there.

It has a little propellor fan to draw the air sample as opposed to an air pump.


Questions for lpc engineer:

1) Is there any way to clear the memory?

2) How much memory is available in this unit. How long will it log data when in continuous mode?

3) What is the life of the laser diode in continuous mode at 75 degrees ambient?

[lpc_engineer]

Hi Kevin,

First, thank you for your purchase. If you, or anyone, would like to talk to us about the features or possible options for the DC1100 please feel free to call or contact us through our website ...

1-877-351-2730
www.dylosproducts.com

As you observed the standard DC1100 does not have a computer hookup. We make one available as an option for $50. With this option data is logged to the PC every minute either through your PC's COM port or to your PC's USB port using a USB-to-COM adapter.

You also observed that the DC1100 uses a fan for creating air movement as opposed to a pump. This is no limitation for most users, however, if you wanted to hook tubing up to inlet as you can on the Fluke then a fan would not provide enough suction.

As for clearing the memory, the units come with the memory cleared, but I can see the need for this so I will start thinking about how to implement that. The unit stores 30 days of history data. It stores minute by minute averages for the past hour, hour by hour averages for the past day, and day by day averages over the past month. If the customer needs more history or needs to know what the counts were at 10:35 4 days ago then our COM port option will let him get all that data on his PC. I tried to address the laser life issue in a previous post. The only really good way to assess laser life is by actual usage. Accelerated life tests which I have conducted lead me to believe several years of life. I think laser life on the DC1100 will be longer than most other laser particle counters.

Hope that helps.

[breathe easy]

I purchased a Dylos DC1100 to check it out. Mine arrived today also.

My first impression is good. It seems to be accurate. Very easy to use. (plug it in and turn it on) You can't go wrong for the price.

Readings in my offices attached to the factory:
My personal office with an Austin Air running - 7,900 particles over 1 micron per cubic foot

The front lobby - 83,000 particles over 1 micron per cubic foot

The front lobby after we walked around on the carpet - 240,000 particles per cubic foot over 1 micron.

Neat!

[Kevin O'Neill]

I left mine on overnight. it read 10,000 small and 0 large particles in my office last night. As soon as I came in it started reading higher on both particle sizes. Now it reads 95,000 small particles and 3,900 large particles. If I get up and move around the readings get higher still. I am impressed. This will be very useful.

More memory would be wonderful. Instead of a serial port, perhaps a USP port? Then you could plug a 1 gig memory stick into it and record every minute for forever. Just unplug the memory stick and plug that into the computer for downloading.

Also it would be nice if monitor mode would sample every minute as an option in addition to every hour. That way you could do short term tests as well as long term tests, and still have long laser life.

I did not see anything on the web site about the serial port option or the small particle size option. I would have purchased the serial port option if I had known about it.

Not griping, just suggesting.

All in all, I am very pleased with the DC1100.

[pmeunier]

I just received the 0.5 uM version.

After starting it and setting it on my desk while I was working, it registered:
small(>0.5 uM) large (>2.5 uM)
35 5 (that would be 3500 and 500 particles)

after vigorously shaking a sweater that had been on a chair for a few months:
300 150 (approximately, the readings fluctuate; it seems that the device displays a running average over about 20 seconds)

after half an hour it settled down to:
30 2

This is with a cheap Duracraft HEPA filter running on "silent" (the lowest speed) nearby. I also have an independently ducted Nutone HEPA filter running continuously in the rest of the house.

I wish I had had it when I was using the Aprilaire 5000. Instead of finding out that a filter was dirty, electrostatically shielded and couldn't capture small particles anymore, by getting sinus inflamation, the counter might have alerted me ahead of time or at least confirmed my suspicions.

The counter is light and simple.
-It wouldn't start at first, but after unplugging and re-connecting the adapter and its cord, it started when I pressed the power button.

-In continuous mode, the noise it makes is comparable to that of my HEPA filter (on "silent"), and is louder than my computer. However, on monitor mode, it makes no noise at all between measurements (every hour). After taking a measurement in monitor mode, it displays the values, which is practical and makes sense. It's easy to look at the data minutes ago, hours ago or days ago by changing the mode.

I really like this unit so far, and would recommend it to whoever is trying to control dust and particles due to strong allergies.

[pmeunier]

hehe, 23 and 0 now. I'm glad I'm not working in Kevin's office

I took it outside and it registered 1600 and 40. That would be a 99% reduction in particles >0.5 uM. Who says that submicron particles can't be controlled at all in a real home . And, this is an old home too, leaky and all.