| 摘要 |
<p>An ice detector of the vibrating element type comprises a tube (32) that vibrates along its longitudinal axis, and is driven by an excitation coil (20) at the natural frequency of the tube (32) is sealed by a diaphragm (35) which has a surface exposed to an air stream in which icing is to be sensed. The exposed diaphragm surface is deflectable during vibration of the tube (32) at a flexible support portion (38) of the diaphragm (35). As ice accumulates on the exposed surface of the flexible support (38) the spring rate or flexibility support (38) changes, thereby changing the natural frequency of the vibration of the tube section (32). The changes in the natural frequency are sensed to determine that ice is accumulating. The diaphragm (35) is of low mass, and small so that stiffness of small amounts of ice significantly changes the spring constant of the flexible support (38) and the diaphragm (35) is shaped to conform to adjacent aerodynamic surfaces (11).</p> |
