What is the difference between calibration and validation?

• A. Calibration adjusts measurement accuracy against a standard; validation confirms a process or system meets requirements.
• B. Calibration verifies a process meets requirements; validation compares instrument readings to a standard.
• C. Calibration and validation both refer to equipment replacement.
• D. Calibration is only for software; validation is only for hardware.

Answer: (A)

Calibration fixes instrument accuracy against a standard, while validation confirms that a process or system meets its requirements and is fit for its intended use. Calibration involves adjusting a measurement device so its readings align with a known reference, often with traceable standards, and it focuses on the precision and correctness of the instrument itself. Validation, on the other hand, asks whether the overall process, method, or system produces acceptable results in real conditions, based on predefined criteria and performance data.

For example, you calibrate a thermometer by comparing its readings to a trusted reference thermometer and adjusting it so the readings match across a range. You validate a manufacturing process by testing whether the process consistently yields products that meet specifications under real operating conditions. The other descriptions mix up who is being checked or what is being adjusted, which isn’t accurate: calibration is not about verifying a process meets requirements, and validation isn’t just about comparing instrument readings to a standard.