| 摘要 |
The sensor 100 comprises a temperature dependent resistor 101 mounted within a protective housing 110. The resistor 101 is connected to external circuitry via a pair of connecting wires 102. In use, variations in temperature of the exhaust gas cause a variation in the temperature experienced by the resistor 101 and consequently, the resistance of the resistor 101 also varies. The resistor 101 is mounted in a projecting end portion 111 of the housing which is of narrower cross-section than the bulk of the housing 110. The housing 110 is filled with a filler material 103. The filler material 103 provides support to the resistor 101 and the wires 102. In the present invention, unlike in prior art sensors, the filler material does not completely fill the housing 110. Instead a gap 104 is provided which is crossed by the wires 102. The gap 104 interrupts heat flow through the filler material and thus improves the thermal isolation of the resistor 101 and thereby the accuracy of the sensor 100. In an alternative embodiment, the sensor 100 additionally comprises an additional heat exchange element 105. The provision of the additional heat exchange element 105 improves the flow of heat from the exhaust gas to the resistor 101, thus providing a faster response when the temperature rapidy changes and higher measurement accuracy. |
