A.0.00002~20Pa B.20~20000Hz C.75~120dB D.80~12000 Hz
A.40~120dB(A) B.10~75dB(A) C.80~160dB(A) D.25~85dB(A)
A.0.01~0.015mm B.0.1~0.15mm C.0.03~0.05mm D.0.001~0.005mm