This situation will lead to inaccurate measurements and large errors. The failure phenomenon is that when the sphygmomanometer switch is turned on, the convexity of the mercury column in the glass tube is lower than the zero mark, or the column or bubble appears during the pressurization. phenomenon. At the same time scattered mercury beads can be seen inside the sphygmomanometer box.
There are two causes of human exposure to mercury leakage and failure of the sphygmomanometer components. The former is dominated by the former. The components that cause mercury leakage sphygmomanometers usually have a switching axis and a mercury storage bottle holder. Since the two are not well-matched, the pressurized pressure causes the mercury to spray outward. When such a failure occurs, the switch axis or the base of the mercury storage bottle should be promptly replaced. The human factor refers to improper use of medical personnel.
The sphygmomanometer should be tilted 450 or more after use to allow mercury to flow back into the mercury storage bottle and close the switch to close the mercury in the mercury storage bottle. The mistake that users often make is that they either do not close the switch and the mercury in the glass tube leaks from the upper end of the glass tube when the lid is closed; the switch is closed without tilting, and the mercury below the line is zero. It was kept out of the mercury storage bottle and left in the indicating glass tube. After closing the lid, this part of the mercury leaked; or the next time the lid was opened, the residual mercury did not return. Before the zero mark was merged with the mercury that came out of the mercury storage bottle, the user started to pressurize, causing the upper piece of mercury to spray from the top of the glass tube.
In our work, we used a simple method of adding mercury: After sucking an appropriate amount of mercury from the reserve mercury with a syringe with a needle, open the upper cover of the sphygmomanometer, open the mercury storage bottle switch, and put the needle from Insert the small hole in the upper end of the glass tube into the small hole, gradually inject mercury, and gently vibrate the sphygmomanometer, so that the injected mercury and mercury poured from the mercury storage bottle merged, the amount of mercury injection to meet the requirements of the zero error shall prevail The small diameter needle should be used to avoid damaging the filter.