What are the differences between equipment “Calibration” and “Validation”? Which equipment needs them?

“Calibration” and “validation” are related but distinct concepts in quality assurance. “Calibration” is the process of comparing and adjusting the reading of a measuring instrument, such as a thermometer or weighing scale, against a recognised and more accurate standard to ensure the reading is accurate. It is a periodic activity carried out on an individual instrument. For example, sending your warehouse thermometer to a qualified laboratory each year to compare it with the laboratory’s standard thermometer is calibration. “Validation” is a broader, more systematic process that provides objective evidence that a process, system or item of equipment can consistently produce results that meet predetermined specifications and quality attributes. It does more than check accuracy: it demonstrates reliability and stability. For example, temperature mapping of a new cold room demonstrates that every corner can consistently be maintained at 2–8°C. This is a systematic validation process.