Noise Analyzer and Sound Level Meter Operating Guide
Noise analyzers and sound level meters measure sound pressure levels for occupational noise assessment, environmental monitoring, and product noise testing.
I. Measurement Setup
- Calibration: Calibrate the instrument with an acoustic calibrator before and after each measurement session.
- Frequency Weighting: Select A-weighting for most environmental and occupational measurements as it approximates human hearing response. C-weighting for peak sound pressure measurements. Z-weighting (flat) for unweighted measurements.
- Time Weighting: Fast weighting for varying noise. Slow weighting for more stable readings. Impulse for short-duration sounds.
- Range: Set the measurement range to accommodate the expected sound levels without overload or under-range conditions.
II. Measurement Procedures
- Environmental Noise: Measure at the assessment location with the microphone at the appropriate height. Use a windscreen outdoors. Record measurement duration, weather conditions, and dominant noise sources.
- Occupational Noise: Position the microphone at the operator's ear position (without the operator present for area measurements). Measure during representative work activities.
- Product Testing: Measure in an anechoic or semi-anechoic chamber. Follow applicable product test standards for microphone positions and operating conditions.
III. Data Analysis
- Equivalent Continuous Level (Leq): The energy-averaged sound level over the measurement period
- Statistical Levels: L10, L50, L90 representing levels exceeded for ten, fifty, and ninety percent of the measurement time
- Peak Level: The maximum instantaneous sound pressure level, important for impulsive noise assessment
IV. Maintenance
- Calibrate acoustically before each use
- Keep the microphone clean and dry; store with desiccant
- Replace windscreens when torn or degraded
- Send for laboratory calibration and certification annually
- Check battery condition before extended measurements
