... board is fast heating-raising, heating evenly, high thermal efficiency, long span life... Cast copper heating board.size:190*190 mm 20mm ... and other devices. Aluminum heater (circle) with the characteristics of long life, good insulation properties, mechanical performance, corrosion-resistant, anti- ... if the insulation resistance of less than 1 ohm a long-term, baking in the oven with 200 for about 5 ...