... Type 2 and GB/T3785 compliant * Multifunctional and with 30-130dB wide range and built-in calibration signal of 94dB at ... , Leq, Lmax, LN. * Measurement range: * Lp: 30~130dB (A), 35~130dB (C), 40~130dB (F) * Leq: 30-130dB (10s, 1m, 5m, 10m, 15m, 30m, 1h ... backlight * Built-in battery condition indicator * Alarm: Electron, adjusable, 30-130dB set, LED and optional relay contact (NC) output* Power off ...