... Option 3).Meets IEC 651, Type 2 Class Sound Level Meter Digital Sound MeterDecibel Meter AZ-8921/8922 DIGITAL DISPLAY WITH ANALOG ... , MAX HOLD ! RS232 INTERFACE ! MEETS IEC 651, TYPE 2 CLASS !FEATURE Meets IEC 651;ANSI S1.4, type2 standard. Quasi-Analog ... Stop bit, 8 Data bits. N: xxx, xdB Monitor the sound levels from traffic noise, alarm systems and workplace machinery, Multi ...