Calibration refers to checking or adjusting the accuracy of the measuring instruments.
- All instruments must be calibrated (according to the manufacturer's
instructions) to ensure measurement accuracy. [29 CFR 1910.95(d)(2)(ii)]
- Calibration should be performed before and after each day of use and whenever the temperature or relative humidity changes significantly.
- Prior to and immediately after taking measurements, it is a good practice to check, using a calibrator, the ability of the sound level
instrument to correctly measure sound levels.
- As long as the sound level readout is within 0.2 decibels (dB) of the known source, it is suggested that no calibration adjustments be
made. If large fluctuations in the level occur (more than 1 dB), then either the calibrator or the instrument may have a problem.