What is a Sound Level Meter?

A sound level meter (SLM) measures sound pressure level in decibels (dB). It is commonly used to check noise exposure, verify compliance limits, and troubleshoot noisy equipment or spaces.

 

Why Monitor Sound Levels?

Monitoring helps you find where/when noise exceeds safe or acceptable limits, so you can reduce exposure and prevent hearing loss or disturbance.

Type of Sound level Meter

Performance Class (Accuracy) per IEC 61672

Many regulations specify an instrument accuracy class (commonly per IEC 61672). Class 1 and Class 2 indicate measurement tolerance (accuracy) across defined frequency and level ranges.

  • Class 1 (precision): Higher accuracy for compliance-grade work (e.g., environmental surveys, detailed studies).
  • Class 2 (general purpose): Routine checks and screening surveys where allowed by the method.

Note (ANSI Type): Some documents use the older ANSI S1.4 “Type” system (Type 0/1/2/3) to describe performance tolerances. In general, Type 0 is the most stringent, Type 1 is precision, and Type 2 is general purpose (Type 3 is typically for survey/screening). IEC 61672 uses Class 1 and Class 2; Type 1 is often roughly compared to Class 1, and Type 2 to Class 2, but requirements are not automatically interchangeable—follow the applicable standard/method.

Instrument Styles (by form factor and typical application) 

  • Standard SLM (handheld): Spot checks and short surveys. Common readouts: SPL, LAeq, Lmax.

  • Sound level datalogger: Records time-stamped levels at set intervals for unattended, long-duration studies.

  • Noise dosimeter: Worn by a person to measure cumulative exposure over a shift (occupational programs).

  • Sound level monitor (fixed): Continuous monitoring with real-time display, alarms, and/or network reporting.

  • Octave band analyzer: Adds 1/1 or 1/3 octave bands to identify dominant frequencies for diagnostics and controls.

 

What is ‘A’ and ‘C’ Frequency Weighting?

Frequency weighting shapes how the meter “hears” sound. A-weighting approximates human hearing and is commonly used for workplace/environmental reporting. C-weighting is flatter (more low-frequency content) and is often used for machinery and peak/impact evaluation.

 

What is the significance of FAST / SLOW Response Time?

Fast and Slow control how quickly the reading updates. Fast responds quickly to changes, while “Slow” provides a steadier, averaged reading often used in noise surveys.

 

Check out the full offering here

 

Back to top