... /8922 1).30-130dB.Backlight(AZ-8922), 2).RS-232 for Option 3). ... Type 2 Class Sound Level Meter Digital Sound MeterDecibel Meter AZ-8921/8922DIGITAL DISPLAY WITH ANALOG GRAPH! BACKGROUND NOISE ABSORBER ... 10-dB steps:30-80dB, 40-90dB, 50-100dB, 60-110dB, 70-120dB, 80-130dB. Accuracy :±1.5dB ( ... temperature :0~50,10~90%RH Storage temperature :-20~60 Meter includes hard ABS case, battery, manual. Battery life ...