Technical Guide

Device Calibration Guide

Optimize your measurements with proper calibration techniques

6 min read
December 2024

While our decibel meter provides reliable reference measurements out of the box, understanding calibration principles helps you achieve the best possible accuracy for your specific device. Different microphones have varying sensitivities, and environmental factors can affect readings. This guide explains how to verify and optimize your measurement accuracy.

Why Calibration Matters

Device Variations

Every device has unique microphone characteristics:

  • Sensitivity differences between manufacturers
  • Frequency response variations
  • Directional patterns (omnidirectional vs directional)
  • Age-related degradation
  • Software processing differences

Environmental Factors

External conditions affecting accuracy:

  • Temperature and humidity effects
  • Atmospheric pressure variations
  • Wind and air movement
  • Electromagnetic interference
  • Case or cover obstruction

Calibration Methods

Method 1: Reference Sound Source

Compare your readings with a known sound source or calibrated meter.

Using a Calibrated Meter

  1. 1. Place both meters at the same distance from a steady sound source
  2. 2. Ensure both microphones are at the same angle and height
  3. 3. Record readings from both devices simultaneously
  4. 4. Note the difference for future reference

Using Standard Sounds

Common reference levels: Normal conversation (60-65 dB at 1 meter), vacuum cleaner (70-75 dB at 1 meter), alarm clock (80-85 dB at 30 cm).

Method 2: Relative Calibration

Establish consistency across multiple measurements for tracking changes.

Quiet Room Test

Measure in the quietest room available. Should read 30-40 dB. If significantly different, note the offset.

Consistency Check

Measure the same sound multiple times. Readings should be within ±2 dB for a properly functioning microphone.

Calibration Best Practices

Do's

  • Test in multiple environments
  • Keep microphone clean
  • Document your offsets
  • Regular consistency checks
  • Use same device position

Don'ts

  • Expect laboratory precision
  • Calibrate in windy conditions
  • Use damaged devices
  • Ignore case effects
  • Mix device orientations

Tips

  • Remove phone cases
  • Clean microphone port
  • Avoid extreme temperatures
  • Test at multiple frequencies
  • Keep records of tests

Device-Specific Considerations

Smartphones

Most smartphones have omnidirectional microphones optimized for voice:

  • iPhone: Generally consistent, microphone at bottom
  • Android: Varies by manufacturer, check microphone location
  • Tablets: Often multiple microphones, use primary one

Laptops & Desktops

Computer microphones vary widely in quality:

  • Built-in mics: Lower quality, more variation
  • External USB mics: Better consistency
  • Headset mics: Avoid for measurements