Electrically-driven symmetric plunger gas micro flow standard device

Abstract

The invention discloses an electrically-driven symmetric plunger gas micro flow standard device. A right cylinder is fixed between a right support and a transmission end plate; a left cylinder is fixed between a transmission support and a buffer jar; a plunger, a left cylinder and a right cylinder are horizontally and coaxially installed; the right cylinder is communicated with the left cylinder through a two-way flow indicator; a ball screw is installed between the transmission end plate and the transmission support; the plunger is connected with a T-type connecting block; the shoulder of the T-type connecting block is matched with straight-line guide rails on top surfaces of two sides of the transmission support; the lower portion of the T-type connecting block is fixedly connected with a lead screw nut; a stepping motor with an encoder is connected with the right end of the ball screw through a reduction gear and a diaphragm coupling; a temperature transmitter is installed on the top side of the buffer jar, an inlet of a flow meter to be detected is communicated with the buffer jar; a flow controller is installed on an outlet of the flow meter to be detected. Because when the plunger moves, the volume variable quantity inside the left cylinder and the variable quantity inside the right cylinder are completely complementary and symmetrical, when detection and verification are conducted, the fluctuation of the temperature and the pressure of gas in the cylinder bodies is reduced, measuring of micro flow is achieved, and meanwhile high-pressure measuring can also be achieved.

Description

technical field [0001] The invention relates to a flow metering device, in particular to an electrically driven symmetrical plunger type gas micro-flow standard device. Background technique [0002] In recent years, the application of small gas flow measurement and control in semiconductor manufacturing, medical chemical industry, food hygiene, bioengineering, high-tech and other fields has become more and more common. The verification and calibration of small flow related instruments has become one of the important branches of the current flow measurement field. First, generally, the range of micro flow is defined below 10mL / min. [0003] At present, there are mainly the following types of micro gas flow measurement technologies: soap film device method, pressure volume temperature time (PVTt) method, mass time (mt) method, constant pressure type, variable volume method (such as piston type), etc. With the development of electromechanical technology, the variable volume me...

AI Technical Summary

Problems solved by technology

When performing small flow measurement, on the one hand, the extrusion of the space will change the state of the gas, which will reduce the measurement accuracy. On the other hand, if the measuring instrument is under high pressure, the power mechanism will have a huge load, which is difficult to achieve.

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