Re: [DIYbio] practical laminar flow benches

If you flood your intake side with particles to see how many get through you will have used up the fouling capacity of your filter with your test. In industrial manufacturing HEPA flow hoods, tests consist of:1)  testing flow rate of air on the clean side; target: not too fast, not too slow 2) industry standard particle detector test on the clean side; target: no particles in detection range 3) pressure drop across the filter; target; not too high

I didn't give quantitative targets because it depends on the industrial requirements. I could see a low budget way of assessing flow rate with a small strip of cloth as in a wind sock and a home made water manometer (for pressure drop). Not sure how to get the particle detection. What is the goal of laminar lab bench? "Nothing gets out?" " Nothing gets in?" Something else? That goal could be the best driver for identifying the best, low-budget effectiveness test.

Cindy

On Thursday, July 17, 2014 7:50:54 AM UTC-7, John Griessen wrote:

On 07/16/2014 11:29 AM, André Esteves wrote:
> Particle or Dust detector?
>
> Maybe something like this?
>
> www.seeedstudio.com/depot/Grove-Dust-Sensor-p-1050.html?cPath=25_127
> <http://www.seeedstudio.com/depot/Grove-Dust-Sensor-p-1050.html?cPath=25_127>

That says, "The output is for PM whose size is around 1 micro meter or larger. We can use the sensor to detect the dust in clean
room. "

so, it sounds very good.  The outcome you want for ensuring your filter is really good is to
see few particles when flooding the filter intake side seams with a certain size of micrometer spheres
to see if any or 'how many' get through.  $16 in small quantities is a good price.

Thanks for this lead to finding components.