The Lenterra Flow Sensor (LFS) system consists of a Drag Force Flow (DFF) sensor, an Optical Interrogator (LOI) and a laptop. The system offers in-line, real-time flow measurement to a number of industries looking to improve process understanding and manufacturing efficiency. 
 
The Drag Force Flow sensor is mounted on a stationary base, and contains two optical strain gauges, made up of Fiber Brag Gratings (FBGs), which are connected to the Optical Interrogator via a fibre optic cable. When immersed in a powder or flowing material, the Drag Force Flow sensor bends under the force of the flow and quantifies the drag force. The amount of bending is measured real-time, in-line, allowing the user to determine in process properties of their materials. 
 
The data is collected via optical fibres that connect the Fiber Brag Gratings with the Optical Interrogator. The interrogator continuously records the Fiber Brag Grating spectra. When the hollow pillar is deflected due to force acting on it, one of the Fiber Brag Gratings becomes stretched and the other one compressed, leading to a shift in wavelength of the spectra.