• Usually ships in 1-2 weeks



  • Response rate: fast, slow, impulse
  • Bandwidth: 20Hz to 8kHz
  • Up to 999,999 readings
  • Adjustable criterion level, exchange rate, & threshold
  • Criterion / threshold levels 30 to 140dB in 0.1dB steps
  • Exchange rate: 3, 4, 5 or 6 dB

What's in the Box

  • Belt clip
  • Clip-on 0.5in microphone with 32in cable
  • Windscreen
  • 9V battery
  • Software
  • USB cable
  • Carrying case


The Extech SL400 Noise Dosimeter is a compact, lightweight dosimeter with USB interface designed to test noise exposure and provide noise surveys for compliance with OSHA, MSHA, DOD, ACGIH, and ISO standards. Includes PC software to control setup and retrieve stored events or analyze real-time measurements.

Applications for the SL400 include:

  • Personal accumulated noise exposure measurement
  • Workplace noise assessment
  • OSHA and other regulatory agency compliances