| 摘要 |
<p>PURPOSE:To achieve not only miniaturization but also the enhancement of sensitivity, by partially heating the intermediate part of at least a pair of the detection electrodes (thermoelectric detection elements) formed on a base material composed of a ceramics semiconductor by a heating electrode. CONSTITUTION:Detection electrodes 2, 3 are formed on the main surface of a base material 1 composed of a ceramics semiconductor using barium titanate in the vicinity of both end parts thereof and heating electrodes 4 for self-heating the base material 1 are formed to both surfaces of the base material 1 at the center part between the electrodes 2, 3. The base material 1 shows the characteristics as a positive characteristic thermistor and, when a current is supplied to the electrode 4, the current supplied part becomes stable at definite temp. Next, when a fluid flows in the direction crossing the electrodes 2, 3, the temp. gradient in the apparatus is different between the upstream and downstream sides of the electrodes 4. Therefore, temp. difference is generated between the electrodes 2, 3 to generate thermoelectromotive force. The flow speed of the fluid can be detected on the basis of said thermoelectromotive force. Further, resistor members 11, 12 are connected between the electrodes 2, 3 and reference voltage and the resistance values thereof are adjusted to make it possible to make the outputs of the electrodes equal to the reference voltage.</p> |
