In a sphygmomanometer, in order to increase cuff pressure at a constant speed, a necessary flow rate is controlled by controlling the voltage of the pump for inflating the cuff and increasing the cuff pressure. In the case that a speed at which the pressure is increased is larger than target even the voltage of the pump is controlled until the necessary flow rate becomes minimum due to small size of the cuff and the measuring portion, inflating with the pump while discharge of air within the cuff from a control valve or a low speed discharge valve is controlled. In a contrary case, suppression of discharge of air from the cuff is controlled. By such control, the sphygmomanometer is capable of increasing pressure at a constant speed from a cuff of a small capability to a large cuff.在血壓計中,藉由控制用以對腕帶供氣並將腕帶壓加壓之泵的電壓,而控制用以將腕帶壓進行等速加壓所需的流量。因為腕帶尺寸及測定部位之尺寸小,即使在該所需的流量變成最小以前控制泵電壓,而加壓速度仍比目標速度還快的情況,係一面以泵供氣,一面進行從控制閥或微速排氣閥排出腕帶內之空氣的控制,使得該所需的流量與從泵所供氣的流量Q呈一致。而在相反的情況,進行抑制來自腕帶之排氣的控制。藉此控制,血壓計係進行等速加壓直到從容量小之腕帶成為大的腕帶為止。
