down to a low steady-state value. Motion of the device causes convection (stirring) in the electrolyte. This brings more I3− to the cathode, which in turn causes an increase in the cell current proportional to the motion. This effect is very sensitive, with extremely small motions causing measurable (and low noise) inertial signals. In practice, the design of the electrodes to create a device with good performance (high linearity, wide dynamic range, low distortion, small settling time) is a complex hydrodynamic problem. Advantages of MET sensors The main advantage of MET sensors over competing inertial technologies is their combination of size, performance and cost. MET sensors have performance comparable to fiber optic gyroscopes (FOGs) and ring laser gyros (RLGs) at a size close to that of MEMS sensors, and at potentially low cost (in the tens to hundreds of dollars range, in production). In addition, the fact that they have a liquid inertial mass with no moving parts makes them rugged and shock tolerant (basic survivability has been demonstrated to >20 kG); they are also inherently radiation hard. Applications Depending on the configuration of the MET device, a variety of inertial sensors can be produced including: Linear accelerometers Linear velocity meters Seismic sensors Seismometers Angular accelerometers Angular rate sensors Gyroscopes Tiltmeters Pressure transducers References Navigational equipment