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Hello,

I look for formaldehyde permeation tubes.
I want to generate a standard air containing low concentrations of formaldehyde. The concentration of formaldehyde would generate between 1µg/m3 and 1 mg/m3.
What do you recommend?

Thanks,
Miella

Hello Miella,

Either you will need two tubes at once with a rather inaccurate rating, or a set up with a very short life perm tube and a very low flow (20 ml/min) that will compromise the accuracy. The temperature for very high rates will be 110 °C.
The range from less than 1 μg/m3 up to about 10 μg/m3 is easy to cover. The range up to 100 μg/m3 is still feasible with minor downsides.
Please note that temperature equilibration takes a very long time and may cause inaccuracies with instable substances such as formaldehyde. Therefore the concentrations in between 1 μg/m3 and 1000 μg/m3 should be achieved by dilution.
Please note that the permeation rate of formaldehyde may change unpredictably due to polymerisation.

Sookie

Thank you Sookie