On either side of the drive coil are magnet and coil assemblies called pickoff coils. These pickoff coils generate a signal detecting the relative motion of the flow tube and the reference tube at each position. The assembly of the pickoff is similar to the drive coil; the coils are fixed to reference tube and the magnet is fixed to the flow tube.
Each coil moves through the uniform magnetic field of the adjacent magnet. The voltage generated from each pickoff coil creates a sine wave. Because the coils are mounted on the reference tube, and the magnet on the opposing flow tube, the sine waves generated represent the relative motion of the single straight tube to the reference tube.