This disclosure describes, in one embodiment, a corrosion monitoring device to monitor fluid flowing to a turbo-machine. The device comprises an elongated body member in the form of a threaded rod. The elongated body member comprises test elements that have material properties responsive to the corrosive components. In one example, the test elements comprise cylindrical tubes that can slide onto the threaded rod. The assembly is positioned in flow streams and, more particularly, finds particular use in the flow stream of fluid found in an inlet system that couples with a turbine (e.g., a gas or steam turbine).