JPS5940137A - Leak testing device - Google Patents

Abstract

PURPOSE:To take a real-time quantitative measurement of leakage, by calibrating the sensitivity of a device easily and simply for the quantitative measurement of leakage, and measuring an increment in the deflection on a leak indicator when a sniffer probe is put close to a leak position of a body to be measured. CONSTITUTION:Before a leak test of the body 1 to be tested is taken, an oil- sealed rotary vacuum pump is actuated to open a standard leak valve 4 and a sample introducing valve 6, measuring an increment Ds of the deflection of the leak indicator of a leak detector 7 detecting the leak of a standard leaking means 5. When the leakage of the standard leaking means 5 is QsatmCC/sec, the minimum detectable leakage Qmin of the leak detector is calculated. The standard valve 4 is closed after the sensitivity of the leak detector 7 is calibrated, and an increment Dx of the deflection of the leak indicator when the sniffer probe 2 is put close to the leak position of the body 1 to be tested is measured to calculate the leakage Q of the body 1 from Q=QminXDxatmCC/sec.

Description

[Detailed Description of the Invention] The present invention relates to a leak test device that performs leak detection using a sniffer method, and in particular, enables real-time measurement of leak amount and facilitates sensitivity calibration of the device during measurement. The present invention relates to a leak test device.

In devices that measure leakage using the conventional sniffer method, a fixed-volume claw hood is applied to the test object filled with a test gas such as helium, and the rise in the concentration of the test gas inside the hood is measured. We have been measuring the amount of leakage. Measuring the amount of leakage using such a conventional method has the disadvantage that it takes time to heat up the test gas because it is stored in the hood, and the amount of leakage cannot be measured in real time.

Therefore, since the suction amount of the sniffer probe and the leakage amount measured by the leak detector number of the test gas sucked in by the sniffer probe do not correspond on a 1 to 1 basis, the suction amount is large and the test gas from the leak point is absorbed together with the surrounding air. 10
Measure and calculate the suction amount of the sniffer probe by using a sniffer probe with an exhaust system configured to allow 0% suction, and also suck the test gas whose concentration is known and the gas that does not contain the test gas through the sniffer probe. Measure the amount of deflection of each leak indicator at this time, calculate the minimum exchangeable leak amount, calibrate the sensitivity of the leak detector, and then measure the leak indicator when the sniffer probe approaches the leak point of the test object. A leak test method using a sniffer method has been proposed in which the amount of leakage is determined in real time by measuring the amount of increase in runout. If this method is implemented using a conventional device, it will take time and effort to calibrate the sensitivity of the leak detector.

The present invention has been made for the purpose of providing a leak test device that can easily perform quantitative measurement of a leak amount in real time in the leak test method using the sniffer method. Namely.

The sniffer probe and leak detector are connected through a sample introduction valve that has a constriction mechanism and is connected to a vacuum pump, and the sniffer probe is moved along the space near the inspection surface of the test object to detect leaks at leak points. The present invention relates to a leak test device for quantitatively measuring the amount of leakage, which is provided with a standard leak mechanism that selectively supplies a fixed amount of leakage between the sniffer probe and the sample introduction valve via a valve. be.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A leak test device which is an embodiment of the present invention will be described below based on the drawings.

The figure is an explanatory diagram showing the configuration of a leak test device according to an embodiment of the present invention. The test object (1) is filled with helium as a test gas. The sample gas carrier tube (3) is connected to the sniffer probe (2 days old) and is connected to the leak detector (7) via the sample introduction valve (6).The sample gas carrier tube (3) of the sample introduction valve (6) A throttle such as an orifice (not shown) is installed on the 3) side, and an oil rotary vacuum pump (8), for example, is connected to this throttle.The sniffer probe (2) and sample introduction valve (6) are A standard leak means (5) is further connected to the connected sample gas carrier tube (3) via a standard leak valve (4).The standard leak means (5) allows helium to pass through quartz glass to maintain a constant temperature. However, it is not limited to a quartz glass type.

Next, a leak test performed using the embodiment apparatus having the above configuration will be explained. Before performing test on the test object fi+glue, start the oil rotary vacuum pump (8), open the standard leak valve (4) and sample introduction valve (6), and detect the leak from the standard leak means (5). Every single detector (
7) Increase in deflection of the leak indicator (not shown) fi
Measure Ds(div). The amount of increase in film deflection for Q means the amount of increase in deflection of the leak indicator when detecting about 511irn of helium contained in the atmosphere. The leakage (9) of the standard leakage means (5) is expressed as Qs (a tutc(
Aec ), then the minimum commutative leak ffiQmin of the leakage detector is given by the equation Qmin=Qs/Ds(at
mcc/see/d iv). This minimum convertible leakage amount Qmin is calculated and the leakage detector (7)
After performing the sensitivity calibration, close the standard valve (4),
When the sniffer probe (2) is brought close to the leakage point of the test object (1), the deflection of the glue quencher increases by 1D.
Measure x(div). This amount of increase also refers to an increase in the fluctuation in detection of helium contained in the air. The leakage amount Q of the test object (1) is calculated using the formula 9 Q=Qmin XDx(ai
m cc/sec ). In this invention, at the leak point of the test object.

It is necessary for the sniffer probe to suck in 100% of the helium from the leak location along with the surrounding air.
Set the outside diameter of the capillary of the sniffer probe and the exhaust power of the oil rotary vacuum pump so that there is a sufficient amount of suction. However, care must be taken because if the suction amount is increased too much, the minimum exchangeable leak amount will become large and small deflections will not be detected.

Since the apparatus according to the embodiment of the present invention is configured and used as described above, it is possible to easily calibrate the sensitivity of the apparatus in quantitative measurement of the amount of leakage by using the sniffer probe method. By measuring the amount of increase in deflection of the leak indicator when approaching the leak point of the test object, it is possible to quantitatively measure the amount of leak in real time.

According to this invention, sensitivity calibration of the device can be easily performed in a leak test using the sniffer method.

It is possible to provide a leak test device that can quantitatively measure the amount of leak at a leak location in real time.

FIG. 2 is an explanatory diagram showing the configuration of.

(1)... Test object (2)...
Sniffer probe (4)...Standard leak valve (5)...Standard leak means (6)...
・Sample introduction valve (7)... Leak detector (8)... Oil rotary vacuum pump Figure 1

Claims (1)

[Claims] The sniffer probe is connected to the detector through a sample introduction valve that has a squeezing mechanism and is connected to a vacuum pump, and the sniffer probe is moved along the space near the inspection surface of the test object to locate the leak point. 1. A leak test device for quantitatively measuring the amount of leak in a leak test device, wherein a standard leak mechanism is provided between the sniffer probe and the sample introduction valve for selectively supplying a constant amount of leak through a valve.