What mechanism is used to check the precision and accuracy of a test system?

• A. Validation
• B. Verification
• C. Standardization
• D. Calibration

Answer: (D)

Calibration is the process of comparing a test instrument’s readings with known reference standards and adjusting the instrument so its output matches those standards. This directly addresses accuracy by removing systematic error (bias) and helps maintain consistent results, which supports precision as well because the instrument then responds reproducibly under the same conditions.

For example, a blood glucose meter is calibrated with solutions of known concentrations, and any offset is corrected so future readings reflect the true values. If the device drifts, recalibration brings the readings back in line with the standard reference.

Verification, in contrast, checks that the instrument's measurements fall within predefined acceptable limits without changing the instrument. Validation confirms that the overall test method reliably produces the intended clinical result. Standardization focuses on uniform procedures and materials across labs. Therefore, calibration is the mechanism that ensures both accuracy and consistency of the test system.