Vapor sampling device

Device useful for measuring the amounts of at least one selected vapor in an ambient gas mixture, comprising:

• a flat substrate having a shallow cavity therein;
• a flat, elongated detector layer capable of interacting with the vapor to be measured contained within, coextensive with and in contact with the bottom of said cavity;
• multiple flat, porous gas-flow attenuating layers superimposed on, and overlying each other, said cavity and said detector layer and being substantially coextensive with said substrate, at least one of said gas-flow attenuating layers being spaced a short distance apart from and parallel to said detector layer or from another one of said gas-flow attenuating layers so as to form layers of substantially placid gas between all of the layers of said device,
• whereby the effect of turbulence, velocity of movement or other disturbance in the ambient gas mixture is minimized and the amount of vapor to be measured is caused to be a function of diffusion through the said thin layer of placid gas and is substantially independent of velocity of the ambient gas mixture at the interface between the device and the ambient gas mixture.