Why does the hygrometer need to be calibrated before it is used?

A hygrometer needs to be calibrated before use to ensure accurate measurement of humidity levels. Calibration aligns the instrument's readings with known standards, compensating for any manufacturing variances or environmental factors that may affect its performance. Without proper calibration, the hygrometer may provide misleading data, leading to incorrect conclusions or ineffective responses in applications like climate control, agriculture, or scientific research. Regular calibration helps maintain reliability and precision over time.