Thick film electrically resistive tracks

摘要: The inventor has found that, irrespective of track thickness or the material which is constructed, optimum width for a thick film heater in range from 1.2mm to 2.1mm. Further advantage accrues that given resistance longer and may be conformed pattern give improved temperature distribution. A heating element also provided, comprising plurality electrically resistive tracks (8) applied surface an insulative substrate switching means (10) selectively connecting one more said power supply. hence operating varied by changing connected (10).