New approach to maintaining liquid flow rate stability in primary standard calibration facility is proposed. It takes advantage of primary standards with constant static head and does not require high-altitude installation of the pressure tank. To implement the proposed approach, the pressure tank is installed in the water pipeline of the Standard between the pumping station and the measurement pipeline. Pressure in the air cushion above the liquid in this tank is maintained automatically, as well as the liquid level in the pressure tank. It has been demonstrated that in order to stabilize the flow, it is sufficient to employ the controlling impacts in the form of air supply/withdrawal and adjustment of variable-frequency drives of pumps. The air is supplied and withdrawn from the air cushion by a set of critical flow nozzles, which are activated depending on the absolute pressure of air in the cushion. The liquid level in the tank is controlled by adjustment of variable-frequency drives of pumps based on the information on the hydrostatic head (liquid level) in the tank. Experimental study of the flow stabilization system of the National Primary Standard GET 63–2017 for mass and volume of liquid, mass and volumetric flow rates of liquid (Kazan, Russia) confirmed high efficiency of the proposed approach.

提出了一种在一级标准校准设备中保持液体流速稳定性的新方法。它利用具有恒定静压头的主要标准，并且不需要高海拔安装压力罐。为了实施建议的方法，压力罐安装在标准的自来水管道中，位于泵站和测量管道之间。该罐中液体上方的气垫中的压力以及压力罐中的液位会自动保持。已经证明，为了稳定流动，以空气供应/抽出和泵的变频驱动器的调节形式采用控制影响就足够了。空气通过一组临界流量喷嘴从气垫中供应和抽出，根据垫子中空气的绝对压力激活这些功能。储罐中的液位根据储罐中静水压头（液位）的信息，通过调节泵的变频驱动器来控制。针对液体的质量和体积，液体的质量和体积流量（俄罗斯喀山）的国家主要标准GET 63–2017的流量稳定系统的实验研究证实了该方法的高效率。