| 摘要 |
<p>Two discrete self-heating elements (60, 62) are provided in a silicon based sensor structure. The first, ''transfer'' self-heating element (60) receives constant current and elevates the temperature of the sensor structure to a desired initial temperature above ambient. The second, ''sensor'' self-heating element (62) is thermally coupled to the first element and receives a current adjusted based on the difference between ambient temperature and the sensor structure temperature so as to maintain a constant temperature difference. Most of the current flowing through the sensor heating element is thus attributable to fluid flow, and this current can therefore be conveniently used to determine fluid flow parameters (e.g., mass air flow). The elements may comprise thin films which may be interlaced or stacked vertically.</p> |
