Disse Amrani

Thank you for the prompt answer.

I will try to do as you said.

I read an article that presents the result of the calculation using this technique but unfortunately it does not present the formula used.

Thank you

Dear Daljeet Singh Dhanjal

Thank you for the prompt answer. 

Thank you very much. 

Suggest caution - the method presumes that all airborne microbes impact, remain on the agar surface and are culturable.  Are there validating data published for this?

 Dear Daljeet Singh Dhanjal

Your answer will be really helpful. Thank you again.

How is the measure offered for passive (settle plate) sampling  "cfu/dm2/hour" brought to  absolute concentration - "cfu/m2"?

Rosemeire Bueno, 10.1053/jhin.2000.0820

Thanks Luiz Vitor da Silva.

No settle plate method offers valid estimate of microbial concentration in air.

"10.1053/jhin.2000.0820" - Luiz vitro de Silva should read the article he cites. This one address surface contamination NOT concentration in air - specifically " monitoring the microbial surface contamination settling from the air in any environment. "

That is the ONLY valid metric one can claim for settle plates.