Extech 407780A 具有USB的集成声级计，30 -130 dB

Applicable Standards: IEC 61672-1, 60651 and 60804 Type 2, ANSI S1.4 Type 2
Accuracy: ±1.5dB (ref 94dB@1KHz)
Resolution: 0.1dB
Digital Display: 4 digital LCD
Measurement Parameters: SPL, SPL MIN/MAX, SEL, and Leq
Measurement Range: 30dB to 130dB
Linearity Range: 100dB
Measurement Frequency Range: 31.5Hz to 8KHz
Frequency Weighting: A and C
Response: Impulse, Fast and Slow
Microphone: 1/2 " Electret condenser microphone
Sampling time:updated every 0.5s
Bargraph: 4dB steps, 100dB  range, 125ms update
Display: Warning Function
  Overrange Indicator Displayed at the upper limit
  Underrange Indicator Displayed at the lower limit
Analog AC/DC Output 2Vrms (at full scale), 10mVDC/dB
Power Supply: Four 1.5V AA batteries, Optional AC adapter
Battery Life :Approximately 24 hours
Dimensions: 10.4x2.8x0.8" (265x72x21mm)
Weight: 10.9oz (310g)
Complete with windscreen, adjustment screwdriver, USB cable, Windows® compatible software, battery, and case