1. Compare with Calibration Reference Standards Again
If the calibration was performed by a professional institution, after receiving the calibration report, you can conduct a preliminary comparison at home with the calibration results and the standard readings provided by the institution.
If you are verifying the calibration yourself, use a standard mercury sphygmomanometer certified by a hospital, and compare the readings using the following procedure: "Same arm, 2-minute intervals, 3 alternating measurements." If the average difference between the three measurements is ≤5 mmHg, the calibration is effective and accurate.
2. Repeatability Stability Test
Under the exact same posture and environment, take 3 consecutive measurements, 2-minute intervals between each measurement.
If the fluctuation of the three readings is ≤5 mmHg, the device stability after calibration is up to standard. If the fluctuation exceeds 10 mmHg, it indicates that the calibration is not up to standard or that there is still a device malfunction, requiring re-calibration.
3. Eliminate human error caused by operation
During verification, first eliminate the influence of operation problems on the results: confirm that the cuff size is suitable for the arm circumference, the strap is tight enough to insert one finger, the center of the cuff is at the same level as the heart, and rest quietly for more than 5 minutes before measurement; if the results still do not meet the qualified standard after eliminating operation, it means that the calibration is not in place and recalibration is required.
