Will a tabletop mercury column sphygmomanometer still be accurate when measuring over time?

Whether desktop or table sphygmomanometer with a long time will have some error. Generally speaking, it is better to calibrate your sphygmomanometer after two years of use. Calibration of sphygmomanometers in Shanghai Minhe Road (near West Baoxing Road) of the Shanghai Medical Equipment Factory repair department. Replacement of the aging part of the components in the Hetian Road, Minhe Road, Shanghai Medical Equipment Factory store.