DC spark testing generates practically no corona and no heat, and is therefore a gentler test process, DC can be used on foamed insulation and thin insulation.是什么意思_DC spark testing generates practically no corona and no heat, and is therefore a gentler test process, DC can be used on foamed insulation and thin insulation.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句