JPS5822974B2 - When you need to know how to use your computer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a sample introduction device for a mass spectrometer, which is equipped with a channel opening/closing function and a conduction slow J-variation function.

When a sample (gas) is introduced into a high vacuum system such as a mass spectrometer and analyzed, it is necessary to change the amount of sample gas introduced in accordance with the pressure on the sample side.

This is because, regardless of the sample side pressure, it is necessary to keep the internal pressure within a certain range as much as possible and perform analysis under optimal conditions. Therefore, the sample t1 side pressure is large. If it fluctuates, it becomes necessary to use a variable conductance valve that has the ability to vary the sample flow rate.

However, when the atmosphere is introduced into the sample side after the analysis is completed, it is necessary to throttle the variable conductance valve to make the conductance almost infinite or to close the valve almost completely.

When performing analysis under the same conditions again, it is necessary to change the conductance and re-set it to the optimum conditions, but this is not so easy since conventional introduction devices open and close the flow path and adjust the conductance using a single valve mechanism. In addition to being complicated to operate, it takes time to set the conductance of the valve when the pressure changes rapidly, and such conventional methods have the inconvenience of not being able to perform sufficient analysis.

This invention was made in view of such circumstances, and will be described below with reference to the drawings.

FIG. 1 is a longitudinal section of a variable conductance valve with a flow path opening/closing mechanism according to the present invention, and FIG. 2 is an external view.

In both figures, 1 is a needle valve that changes conductance.
2 is a support for the needle valve 1, 3 is a cylindrical on-off valve with an opening/closing function, and 4 is an airtight seal between the inner hole 9H of the valve body 9 and the on-off valve 3 inserted into the inner hole 9H. O-ring for sealing,
5 is a screw hole for attaching a connection flange, 6 is a Q for attaching a connection flange, IJ song groove 7 is a sample outlet, 8 is a Q for closing the valve, IJ song 9/ is a sample introduction path formed in the valve body 9 And 9■ is the mouthpiece.

Further, 10 is an airtight sealing ring between the opening and closing valve 3 and the needle valve 1 inserted in the opening and closing valve 3, and 11 is a mounting screw for the support base 2.

The method of operation is as follows: First, the sample introduction path is opened by rotating the on-off valve 3, and an appropriate conductance is set by appropriately rotating the needle valve 1.

When closing the valve, only the on-off valve 3 is rotated and sealed with the O-ring 8, and when opening it again, by rotating only the on-off valve 3, the same conductance as before can be obtained. can.

The on-off valve 3 can be driven not only manually but also electrically or pneumatically.

In FIG. 3, reference numeral 12 denotes a storage container for an analysis sample, such as a sample (gas) generation chamber.

13 and 14 are variable conductance valves with a flow path opening/closing mechanism shown in FIGS. 1 and 2 according to the present invention, 13 is set to a conductance corresponding to a region of high sample side pressure, and 14 is set to a conductance corresponding to a region of low sample side pressure. Set the corresponding conductance.

15 is a mass spectrometer. Figure 4 shows the specific operation of the apparatus shown in Figure 3. As the sample side pressure decreases over time, the mass spectrometer pressure also decreases, and the mass spectrometer pressure falls below the optimum range. At this stage, the variable conductance valve 14 with flow path opening/closing mechanism is opened, and the pressure is again reduced to the optimum pressure region.

This method shows its true value when the pressure decrease on the sample side is rapid, and when such a process is repeated, the reproducibility of the analysis is completely guaranteed.

Further, the valve provided by the present invention has the advantage that it has an extremely simple structure, can be made compact, and can minimize the volume of dead space within the valve.

In FIG. 4, two variable conductance valves with flow path opening/closing mechanisms are used, but the present invention is not limited to only two.

It also includes operation by electric power or pneumatics, and it is also possible to open and close a variable conductance valve with a flow path opening/closing mechanism automatically and in conjunction with the pressure gauge output of the sample side pressure. This invention encompasses.

The configuration of the variable conductance valve with flow path opening/closing mechanism is not limited to that shown in FIG. 1 either.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal sectional view of a variable conductance valve with an opening/closing mechanism according to the present invention, and FIG. 2 is an external view thereof. FIG. 3 is an example of its application, and FIG. 4 is a diagram showing the operation of the device shown in FIG. 3. 1...Needle valve, 3...Opening/closing valve, 4
, 8゜10...01Jng, 7...Sample outlet, 9...Valve body 9/...Sample introduction path, 12... ...Sample storage container, 13,1
4...Variable conductance valve with flow path opening/closing mechanism,
15...Mass spectrometer.

Claims (1)

[Claims] 1. A valve body having a flow path and a valve port interposed as a part of the flow path, and a valve body that is airtightly inserted into the valve body and is displaced relative to the valve body. a cylindrical on-off valve that opens and closes the flow path by opening and closing the flow path; It is equipped with a variable conductance valve with a flow path opening/closing mechanism consisting of a needle valve that adjusts conductance, and by connecting a sample introduction path for a mass spectrometer to the flow path of the valve, the sample introduction path can be set to an arbitrary conductance. A sample introduction device for a mass spectrometer, characterized in that a sample introduction path can be opened and closed without changing the conductance set therein. 2. A valve body having a flow path and a valve port interposed as a part of the flow path, and a valve body that is airtightly inserted into the valve body and is displaced relative to the valve body to allow the flow to flow. A cylindrical on-off valve that opens and closes a flow path, and a needle valve that is airtightly inserted into the cylindrical on-off valve, is displaced relative to the valve body, and advances and retreats from the valve port to adjust the conductance of the flow path. It has a plurality of variable conductance valves with flow path opening/closing mechanisms, and each of these valves is connected to the sample introduction path for the mass spectrometer on the outskirts of the system. The inductance of each valve Mi + is set correspondingly, and the sample introduction path can be opened and closed by a passage opening/closing mechanism in one of the valves in relation to the sample side pressure I7. Sample introduction device for mass spectrometer.