JPS62222138A - Leak detector - Google Patents

Abstract

PURPOSE:To make it possible to remove undesirable condensation of moisture or an oil component and to reduce the loss time of work, by providing a special pump not exhausting helium to the exhaust system of an analytical pipe in series and increasing the exhaust speed of a high vacuum exhaust pump. CONSTITUTION:For example, a special pump 140 exhausting no helium such as a sorption pump, a cryopump or an ion pump is incorporated between a test value 50 and a high vacuum exhaust pump 100 such as an oil diffusion pump or a turbo molecular pump. By this constitution, the condensable gas degassed from a body 130 to be tested can be absorbed preliminarily in this side of an analytical pipe 90. Therefore, for example, even if the pump 100 has a throttle hole 101, helium passes through the pump 140 and, therefore, the partial pressure of helium entering the analytical pipe 90 does not change. Because the condensable gas is efficiently absorbed by the pump 140, the loss time of work can be reduced.

Description

[Detailed description of the invention] The main character is standing up and standing. The present invention relates to a mass spectrometry type glue detector.

Jυ41 Figure 2 shows the exhaust system of a conventional leak detector.

In the figure, 10 is a connection port for connecting the test object 130 to the manifold, 20 is a vacuum gauge for the manifold, and 3° is a roughing valve provided upstream of the roughing pump 40.

Reference numeral 50 designates a test valve, and a high vacuum pump 100 such as an oil diffusion pump or a turbo molecular pump is connected to the analysis tube side of the test valve 5o. A cold trap 60 is integrally incorporated into the high vacuum pump 100. The analysis tube 90 is connected to the high vacuum pump 1 via the analysis valve 80.
Connected to the low vacuum side of 00. Note that 70 is an analysis tube pressure gauge, and 120 is an auxiliary pump that performs auxiliary evacuation of the high vacuum evacuation pump 100 via the forevalve 110.

In such a leak detector, during a test, the high vacuum pump 10 is used to introduce as much helium leaked from the test object 130 to the analysis tube 90 side.
It is necessary to reduce the pumping speed at zero, and for this purpose a throttle hole 101 is provided at the opening of the high vacuum pump 100.

However, there are various test objects 130.
The inside thereof is not necessarily vacuum-clean, and may contain moisture, oil components, etc., for example.

When performing a leak test on such a test object 130,
As mentioned above, since the high vacuum evacuation pump 100 has the restrictor hole 101, it is difficult to sufficiently exhaust the condensable gas such as moisture and oil components, and therefore it is difficult for the analysis tube 90 to reach the required degree of vacuum. It took a lot of stoppage time.

This invention was made in view of the above circumstances, and it is possible to remove undesirable condensable gases such as moisture and oil components without increasing the pumping speed of the high vacuum pump, thereby reducing the loss time of the above work. It is intended to provide a leak detector.

The leak detector according to the present invention for detecting helium is equipped with a special pump that does not exhaust helium in series with the analysis tube exhaust system.

FIG. 1 shows the exhaust system of a conventional leak detector according to the present invention. In the figure, the same reference numerals as in FIG. 2 indicate the same parts. In this invention, a helium pump such as a sorption pump, a talio pump, an ion pump, etc. A special pump 140 that does not exhaust air is incorporated. Other configurations are the same as the conventional technology.

When constructed in this manner, the leak detector of the present invention incorporates the special pump 140 in series with the analysis tube exhaust system, so that the condensable gas to be decashed from the test object 130 is transferred to the analysis tube 900. This can be easily absorbed in advance.

Therefore, even if the high vacuum exhaust pump 100 has the throttle hole 101, helium is
40, the helium partial pressure entering the analysis tube 90 remains unchanged. In addition, since the condensable gas is efficiently absorbed by the special pump, it is possible to reduce work loss time.

[Brief explanation of drawings]

FIG. 1 shows a conventional exhaust system of a leak detector according to the present invention. Figure 2 shows the exhaust system of a conventional leak detector. 10... Connection port, 20... Vacuum gauge for manifold,
30...Roughing valve, 40...Roughing pump, 50.
...Test valve, 60...Cold trap, 70
...Analysis tube pressure gauge, 80...Analysis valve, 90.
...Analysis tube, 100 ...High vacuum pump, 10
1... Throttle hole, 110... Fore valve, 1
20... Auxiliary pump, 130... Test object, 1
40...Special pump. Patent applicant Shimadzu Corporation Representative Patent attorney Takaharu Ohnishi Figure 1 Figure 2

Claims (1)

[Claims] (1) A leak detector characterized by being equipped with a special pump that does not exhaust helium in series with the analysis tube exhaust system.