... experience 4.best price TL5660 series precise impulse sound level meterIt meets IEC 61672 standard and the first class ... sound meter verification regulations.digital and watch hand display, different level measurementwith impulse, it can accurately test lower limit, upper ... 30dB-138dB(A),40dB-138dB(C),45dB-138dB(linearity)TL5660B(low level): 20dB-135dB(A),32dB-135dB(C),40dB-135dB(linearity)TL5660B ...