I am a student who is interning at a company this summer, and I've been put in charge of its first R&D project which will require me to collect a lot of data. The machine with which I am working is called a Tunnel Finisher. It is essentially a long tunnel through which clothes are pulled in order to dry them and remove wrinkles after a wash cycle. Hot air is blown down on the clothes through louvers from a shaft above the tunnel which leads from a fan that maintains the flow of air. What I would like to do is measure air flow, above the clothes, at the level of the clothes, and below the clothes, at multiple points in the tunnel. Because the air in the tunnel is hot and clothes move through it, this measurement cannot be done manually; I need sensors that can be placed in the tunnel, preferably stuck to the walls, that will provide data while the machine is operating normally. The goal of this endeavor is to reveal dead spots of significantly less air flow in the machine.
I've looked at some different kinds of sensors, but I don't really know what I'm looking for, and I assume what I end up using shouldn't be too expensive. I was hoping someone here could provide some insight as to which air flow sensors, or other type of sensor, I should be looking at for this purpose.