| 摘要 |
A method of manufacturing a thick film resistive heating element (1) comprising the application of one or more thick film resistive tracks (3, 3A, 3B) to the surface of an electrically insulative substrate (2) includes the application of at least one compensating thick film resistive track (6) to the surface of the substrate (2) which is electrically disconnected from said one or more thick film resistive tracks (3, 3A, 3B) at the time of application. By this means, when the resistance of said one or more resistive tracks (3, 3A, 3B), excluding the one or more compensating tracks (6), are measured should this measured resistance vary from a predetermined required value by more than a permitted tolerance then at least one of the compensating resistive tracks (6) can be electrically connected to said one or more resistive tracks (3, 3A, 3B) to bring the total resistance of the tracks (3, 3A, 3B, 6) within the permitted tolerance range. Preferably, each compensating thick film track (6) is printed in parallel with said one or more of the compensating tracks (3, 3A, 3B) whereby electrical connection of one or more of the compensating tracks (6) to said one or more resistive tracks (3, 3A, 3B) decreases the resistance of the electrically connected resistive tracks (3, 3A, 3B, 6) as a whole. |
