| 摘要 |
<p>Fluid flow measuring device comprising elements positioned on the outer wall of a thermally conductive measuring channel and thermally insulated from the environment by an insulating body. The sensor elements can be heated for creating temperature gradient as a function of the fluid flow rate, which temperature gradient can be converted into and electrical measuring signal using a bridge circuit. The bridge circuit comprises four sensor elements which two by two are connected in series and are positioned onto the fluid measuring channel such that of each series circuit one element is positioned on a first section of the fluid measuring channel upstream in relation to a second section of the fluid measuring channel on which the other element of the respective series circuit is positioned, whereby the downstream end of each series circuit is connected to the upstream end of the respective other series circuit, and the electrical measuring signal is available at the junctions within said series circuits. The sensor elements are formed by thin or thick film resistors or integrated semiconductors on the electrically insulating fluid measuring channel respectively on a thin insulating layer on the electrically conducting fluid measuring channel.</p> |
