| 摘要 |
A heating element (2) comprises an electrically resistive track intended to be formed on an electrically insulative substrate (4). A heating unit (10) comprises a heating element (12) and a temperature sensor (14) on a substrate (11), the sensor (14) comprising an electrically resistive track. The track (2,14) consists of a thick film having in the temperature range of from 0 DEG C to 550 DEG C a temperature coefficient of resistance in excess of 0.006 per degree C. The thick film includes a metal and a glass in such proportions as to provide a suitable resistivity and a thermal expansion coefficient to match that of an electrically insulative substrate to which the track is to be applied and to permit adhesion of the track to the substrate. The considerable variation of the resistance of the track with temperature provides advantages in both of the aforementioned applications. |
