| 摘要 |
A liquid heating vessel comprises a thick film hater having a generally planar metallic substrate (8), an electrically insulating layer (6) on said substrate (8) and a resistive heating track (2) applied to said insulating layer. The vessel is also provided with means, such as a variation in the power density of the heating track (2) across a diameter, to minimise tensile strain of the insulating layer (6) of said heater during operation. In one particular arrangement the distribution of power density is arranged so that the power density in the peripheral region (2a, 2b) of the heater is higher than at least a radially intermediate region (2e, 2f) of the heater.
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