sensor is also capable of measuring flow in both directions, which sometimes occur in pulsating situations. Technological progress allows this kind of sensor to be manufactured on the microscopic scale as microsensors using microelectromechanical systems technology. Such a microsensor reaches a significantly higher speed and sensitivity compared with macroscopic approaches. See also MEMS sensor generations. Laminar flow elements Laminar flow elements measure the volumetric flow of gases directly. They operate on the principle that, given laminar flow, the pressure difference across a pipe is linearly proportional to the flow rate. Laminar flow conditions are present in a gas when the Reynolds number of the gas is below the critical figure. The viscosity of the fluid must be compensated for in the result. Laminar flow elements are usually constructed from a large number of parallel pipes to achieve the required flow rating. See also List of sensors Manifold absolute pressure (MAP) References Engine sensors Flow meters Gas technologies Mass