SprintIR Diffusion Membrane Cap

thingiverse

This is a custom add-on cap that converts a SprintIR-6S CO2 sensor to use diffusion instead of flow-through. Although there are other models of SprintIR and ExplorIR sensors that are diffusion-based out of the box, they are not always in stock. You can buy a flow-through sensor, but if the gas flow isn't highly controlled and dehumidified then the sensor may return erroneous values. Since the operating principle is otherwise exactly the same as that of other models that use diffusion, the SprintIR-6S can be converted to have a diffusion membrane using this model. All you have to do is print it and place it on the sensor. It's a light friction-fit that's snug so that it stays on reliably but is not difficult to remove by hand. I don't know if this model fits other SprintIR versions. Since an OpenSCAD file is included, you can always adjust accordingly.