解答：ESD的防护等级按照HBM模型分为：                                                         

Class Voltage Range
0 < 250 V
1A 250 to < 500 V
1B 500 to < 1000 V
1C 1000 to < 2000 V
2 2000 to < 4000 V
3A 4000 to < 8000 V
3B ≥8000 V                                                                  

使用静电枪对产品进行放电试验，来判定ESD的防护等级。