1. Improper operation
Incorrect posture during measurement, such as arm position too high or too low.
The cuff is tied too loosely or too tightly.
Not resting enough before measurement.
2. Aging or damage of blood pressure monitor components
Although calibrated, some internal components, such as rubber tubes, age and leak after a period of use.
The glass tube of the mercury sphygmomanometer is scratched or damaged.
3. Environmental factors
The measurement environment temperature is too high or too low, which affects the performance of the sphygmomanometer.
The surrounding environment is noisy, causing the subject to be nervous and affecting the blood pressure measurement value.
4. Physiological changes of the subject
The subject's physical condition changes, such as illness, obesity, and weight loss, may affect the blood pressure measurement results.
5. The sphygmomanometer is damaged again
After calibration, it is damaged by external forces such as collision and fall.
6. Failure to perform regular maintenance
Even after calibration, simple inspections and maintenance are required regularly, such as cleaning and checking whether the components are normal. If not performed, inaccuracies may result.
