IEC60990—2000中一句话理解不明确,请大家帮忙!

在看IEC60990—2000标准,ANNEX G中关于阻抗的元件选用,G1.2中CS的选用中有:0.1uF film capacitors rated 250V a.c have been measured for resonance at about 3MHz.是什么意思?是说测试电容在3Mz时候,无谐震么?怎么测试?