During calibration, why should accuracy be within ±2 mmHg?

• A. To ensure readings are precise and clinically meaningful.
• B. To please the manufacturer.
• C. To calibrate faster.
• D. To save power.

Answer: (A)

During calibration, the aim is for the device to measure arterial pressure as close to the true value as possible. Keeping the error within ±2 mmHg means readings are precise enough that real changes in a patient’s blood pressure are reflected accurately, making clinical decisions reliable. If the calibration tolerance were larger, a patient could be misclassified as hypertensive or normotensive, or a treatment decision could be inappropriate. This level of precision ensures readings are clinically meaningful and consistent over time and across devices. The other options—pleasing the manufacturer, calibrating faster, or saving power—don’t improve diagnostic accuracy or patient safety.