What is needed to ensure the accuracy of test instruments?

Calibration is essential for ensuring the accuracy of test instruments because it involves comparing the instrument's measurements to a known standard or reference. Through calibration, any discrepancies between the instrument's readings and the standard are identified and adjusted. This process accounts for any drift or changes in the instrument's performance over time, thereby ensuring that it delivers precise and reliable measurements.

While correction factors can help adjust readings based on known biases, they do not replace the need for calibration. Regular maintenance is important for the overall functionality of test instruments, but it does not directly address measurement accuracy unless it includes periodic calibration. Replacement may be required for faulty instruments, but it is not a proactive measure to ensure accuracy for instruments in operational condition. Therefore, calibration stands out as the crucial step in maintaining the accuracy of test instruments.