JPH01262432A - Diaphragm capacity type vacuum gauge - Google Patents

Abstract

PURPOSE:To remove reactive gas completely, to prevent corrosion in an instrument, and to improve the life of the instrument by admitting inert gas whose flow rate is controlled to between a diaphragm for pressure measurement and a baffle plate. CONSTITUTION:The instrument is constituted by piping an inert gas intake pipe 7 to a 2nd chamber 2b so that the pipe penetrates the side wall of a hous ing 1 between the diaphragm 4 for pressure measurement and the bottom part of a pressure transducer 2, and a flow rate controller 6 and a valve 5 are inter posed in the middle of the conduit. The reactive gas remaining in the vacuum gauge is discharged to the side of a vacuum device with the admitted inert gas and the 2nd chamber 2b in the vacuum gauge is filled with the inert gas. The valve 5 is opened after processing and the flow rate is controlled by the flow rate controller 6 to admit the inert gas to the 2nd chamber 2b of the vacuum gauge with pressure which does not exceed a measurement pressure range. Then the valve 5 is closed before a next process is entered to evacuate the vacuum gauge, which is adjusted to zero. Thus, the reactive gas is removed completely, the corrosion in the instrument is prevented, and the life of the instrument is improved.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a diaphragm capacitive vacuum gauge.

[Conventional technology]

A conventional diaphragm capacitive vacuum gauge (hereinafter referred to as a vacuum gauge) has a pressure transducer 2 built into a housing 1 as shown in FIG. It has a first chamber 2a and a second chamber 2b.
An electrode 3 that forms a capacitance between the chamber 2a and the pressure measuring diaphragm 4 is installed, and the second chamber 2b is connected to a vacuum device 8 shown in FIG. 4 through a connecting pipe 14 opened in a baffle plate 13. There is.

The vacuum device 8 has upper and lower electrodes 7.11, a vacuum pump 12 is connected thereto, and a wafer 10 is mounted on the lower electrode 11.

When this vacuum gauge is used in a vacuum device using active gas, the space between the pressure measuring diaphragm 4 and the baffle plate 13 is filled with the active gas introduced into the vacuum device. The active gas in the vacuum gauge was removed together with the active gas in the vacuum device to which the diaphragm capacitive vacuum gauge was attached by exhausting the vacuum pump 12 attached to the vacuum device. An isolation valve was also provided to prevent atmospheric air from entering the vacuum gauge when the vacuum in the vacuum device was broken.

[Problem to be solved by the invention]

The conventional vacuum gauge described above uses a vacuum pump 12 connected to a vacuum device 18 to exhaust the active gas inside the vacuum device 8 as well as the active gas that has entered the vacuum gauge during pressure measurement. Ensures vacuum sealing even when the gas is not completely removed and the pressure measuring diaphragm is corroded by the active gas remaining inside the vacuum gauge, or when an isolation valve is installed between the vacuum device and the vacuum gauge. If this is not done, the atmosphere will leak into the vacuum gauge, and the inside of the vacuum gauge will be corroded due to the reaction between the moisture contained in the atmosphere and the active gas.

An object of the present invention is to provide a diaphragm capacitive vacuum gauge that solves the above problems.

[Differences between the invention and the prior art]

The vacuum gauge of the present invention differs from the conventional diaphragm capacitance type vacuum gauge described above in that an inert gas is introduced into the vacuum gauge to actively remove active gas remaining within the vacuum gauge.

[Means to solve the problem]

In order to solve the above problem a, the diaphragm capacitive vacuum gauge of the present invention has a first chamber and a second chamber separated by a diaphragm in the pressure transducer, and a chamber in the first chamber facing the diaphragm. In a diaphragm capacitive vacuum gauge in which an electrode is installed and a second chamber is communicated with a vacuum device, an inert gas introduction pipe for introducing an inert gas into the second chamber is connected, and an inert gas introduction pipe is connected to the conduit of the introduction pipe. It is equipped with a flow rate regulator that controls the flow rate of active gas.

〔Example〕

Hereinafter, the vacuum gauge of the present invention will be explained with reference to the drawings.

(Example 1) FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.

The inside of the pressure transducer 2 protected by the casing 1 is divided into a first chamber 2a and a second chamber 2b by a pressure measurement partition llA4, the electrode 3 is installed in the first chamber 2a, and the transducer is installed in the second chamber 2b. the fourth through the connecting pipe 14 opened in the second wall
It is connected within the vacuum device 8 shown in the figure. The above configuration is the same as the conventional one.

In the diaphragm capacitive vacuum gauge of the present invention, an inert gas introduction pipe 7 is installed in the side wall between the pressure measuring diaphragm 4 and the bottom of the pressure transducer 2 through the housing 1 and into the second chamber 2b. ,
A flow regulator 6 and a valve 5 are interposed in the middle of the pipe.

In the present invention, the active gas remaining in the vacuum gauge is discharged to the vacuum device side by the introduced inert gas, and the second chamber 2b in the vacuum gauge is filled with the inert gas.

After the treatment, the valve 5 is opened, the flow rate is controlled by the flow rate regulator 6, and the inert gas is introduced into the second chamber 2b of the vacuum gauge at a pressure that does not exceed the measurement pressure range. Shortly before starting the next process, close the valve 5 to evacuate the vacuum gauge and zero-adjust the vacuum gauge.

(Embodiment 2) FIG. 2 is a longitudinal sectional view showing a second embodiment of the diaphragm capacitive vacuum gauge of the present invention. In the diaphragm capacitive vacuum gauge of this embodiment, the bottoms of the casing 1 and the pressure transducer 2 are inclined downward toward the connecting pipe 14, forming a forest shape. This reduces the area where gas accumulates and allows effective replacement of active gas with inert gas.

〔Effect of the invention〕

As explained above, according to the diaphragm capacitive vacuum gauge of the present invention, reactive gas can be completely removed by introducing an inert gas with a controlled flow rate between the pressure measuring diaphragm and the baffle plate. This prevents corrosion inside the diaphragm capacitance type vacuum gauge due to reactive gases and improves the life characteristics of the diaphragm capacitance type vacuum gauge.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing a first embodiment of the diaphragm capacitive vacuum gauge of the present invention, and FIG. 2 is a longitudinal sectional view showing a second embodiment of the diaphragm capacitive vacuum gauge of the present invention.
Figure 3 is a vertical cross-sectional view of a conventional diaphragm capacitive vacuum gauge, and Figure 4 shows the conventional diaphragm capacitive vacuum gauge shown in Figure 3 installed in a vacuum device. FIG.

Claims (1)

[Claims] (1) A first partition inside the pressure transducer separated by a diaphragm.
In a diaphragm capacitive vacuum gauge having a chamber and a second chamber, an electrode is installed in the first chamber facing the diaphragm, and the second chamber is communicated with a vacuum device, the second chamber is filled with an inert gas. 1. A diaphragm capacitive vacuum gauge, characterized in that an inert gas introduction tube for introducing the gas is connected to the inert gas introduction tube, and a flow rate regulator for controlling the flow rate of the inert gas is equipped in the conduit of the introduction tube.