Why is instrument calibration important and how often should it be done?

Calibration ensures measurement accuracy by comparing instrument readings against known standards and adjusting if necessary. It is important because: instruments drift over time, environmental conditions affect readings, components age, and regulations often require traceable calibration. Calibration frequency depends on: measurement criticality, stability of instrument, environmental conditions, manufacturer recommendations, and industry standards. Typical intervals range from annually to daily for critical measurements. Calibration records provide traceability to national standards.