Vapor headspace sampling is a method to capture any compounds that may be off-gassed by samples during relative humidity conditioning.

To sample the headspace of the R.H. chamber, a large gauge needle is inserted through the silicone stopper in the back of the R.H. chamber. The needle is connected to a hose that can attach to a syringe using Luer Lock fittings. The headspace of the chamber can then be captured in the syringe and transferred to a vacuum vial for testing.