Help, please û lab to sort wood dust by size 1

[tomwalz]

Help, please – lab to sort wood dust by size

There is a company called Dylos (

http://www.dylosproducts.com/)

that has a cool little particle counter for airborne particles. Mine measures .5 and 5 micron sizes. What I would like to do is find a lab that can analyze dry wood dust (dry is important) and give me some idea of particle size distribution either by particle count or weight.

The idea is to take the two readings and be able to relate them to OSHA and ACGIH standards using weight per cubic meter.


My usual labs can’t do it so I am looking for a referral to a lab.

Thank you,
Tom


Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

 

[Compositepro]

Particle size is a much more complex subject than most people realize. For example, what is the size of a wood splinter? One number cannot describe it. So how can one number describe a distribution?

In any case, the answer to your question is not so much technical as legal. You are dealing with safety regulations and test methods will be specified by the regulations. Taking the sample correctly is the first step. OSHA does not care about the size of your dust, but the size of the dust in the air that an employee is exposed to. So you will probably have to put a sample pump on a worker and it will draw air though a filter for 15 minutes or 8 hours and then the filter is analyzed by a lab certified to that particular test method.

 

[tomwalz]

Dear Compositepro,

You are correct, of course, and did a beautiful job explaining the situation.

However the meters exist and are being used. I suppose it could be compared to using a CMM to measure a part versus using a Go / No Go gauge.

With your expertise I would appreciate any advice you cared to offer on developing a simple rule of thumb based on available information.

Thank you,
tom


Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

 

[Compositepro]

Sorry, I completely overlooked your link to Dylos. What they make is designed for consumer use and might provide some qualitatively useful information (is dust increasing or decreasing). I've used a $50,000 laser partcle counter, and getting it to read close to the same number when testing the same sample multiple times was very difficult. The Dylos instrument also appears to designed for relatively clean home environments. If it could be used for in industrial environments they would have a much more lucrative market. I'm sure there is good reason that they are not selling to the industrial market.

 

[tomwalz]

Dylos is brand new and really doesn't understand the industrial market. Their original concept was home use, as you said, for allergies.

One of the folks on Sawmill Creek (woodworkers’ forum) bought one and started this whole thing. Now a couple hundred have them and no one is sure what the results mean.

We do a newsletter for the saw and tool industry and I thought this might make a good article.

I thought about selling the instruments but they want a really large investment in inventory for a small discount so it doesn’t make sense financially.

I agree with you on the industrial market. We have a grain elevator here in town that had a dust explosion a few years ago as just one example.

There is a test in the saw industry. When you braze up a saw with new tips you hold it in one hand and use an 18” stick to beat on the tips with the other hand. It is a very crude test but has turned out to be surprising helpful as a go / no go test.

We give away really cheap eye droppers to use as a water break test. The wider the drop, the cleaner the surface is. Again a really crude test but considerably better than no test at all.

I hope to come up with some sort of simple metric for the Dylos meter.

Tom


Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

 

[btrueblood]

Tom,

Dunno about a lab providing the service, everywhere I've been that needed to do particulate counting (for cleanliness spec. compliance, typ. aerospace fuel and hydraulics systems) we did it ourselves using Millipore filters, vacuum pumps, microscopes, etc.. FED-STD-209 I believe was the old spec. for cleanrooms (particulate counts of air), of course that spec. is now obsolete (replaced by ISO 14644?), you could try searching for labs that test for compliance to those standards, they will at least have the right equipment.

 

[unclesyd]

Ran across this outfit that looks like they could do the job. Got the right name.

http://www.particletechlabs.com/Services/size.htm

 

[tomwalz]

That's it. Thank you sir.

Tom

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com