Leak detector

Patent metadata

Field	Value
Publication number	US-9632067-B2
Application number	US-201514833428-A
Country	US
Kind code	B2
Filing date	Aug 24, 2015
Priority date	Sep 3, 2010
Publication date	Apr 25, 2017
Grant date	Apr 25, 2017

Abstract

The invention relates to a leak detector comprising a first sensor for detecting a gas component (helium) in a gas taken in. Because the sensor is susceptible to saturation or contamination, a second sensor is provided. The sensor is a thermal conductivity sensor. The thermal conductivity sensor has a lower detection sensitivity, yet, at a high concentration of the gas component, it does not risk being contaminated. The two sensors together allow for a large detection range, from extremely sensitive measurements to instances with high concentrations of the gas components as those which can occur with gross leaks.

First claim

The invention claimed is:

1. A leak detector with a vacuum pump device through which gas is taken in, and a first sensor for detecting at least one gas component in the gas taken in, the first sensor is a saturable gas-selective sensor,
wherein a second sensor is a thermal conductivity sensor and is provided to detect the thermal conductivity of the gas taken in, and a signal-receiving control device for switching the first sensor to a blind mode when a total pressure is above a limit value, the first sensor covering a low total pressure range and the second sensor covering a high total pressure range.

2. The leak detector of claim 1 , wherein a valve is arranged upstream of the first sensor in a gas flow of gas taken in, said valve being switched by the signal-receiving control device to a closed state in order to realize the blind mode.

3. The leak detector of claim 1 , wherein the first sensor comprises a heatable, selectively gas-permeable membrane, and heating the membrane is deactivated in order to realize the blind mode.

4. The leak detector of claim 1 , wherein a sniffer probe is provided for taking in gas from the atmosphere, and the first sensor is included in a measuring conduit and the second sensor is included in an intake conduit, the intake conduit leading directly from the sniffer probe to the vacuum pump device and carrying a higher flow rate than the measuring conduit, so as to increase distance sensitivity.

5. The leak detector of claim 1 , wherein the second sensor is arranged at a position where a constant total pressure prevails that approximates atmospheric pressure.

6. The leak detector of claim 1 , further comprising a bypass conduit including valves controlled by the signal-receiving control device.

7. The leak detector of claim 5 , wherein the second sensor is arranged in an intake conduit or at an air outlet of the leak detector.

8. A leak detector with a vacuum pump device through which gas is taken in, and a first sensor for detecting at least one gas component in the gas taken in, the first sensor is a saturable gas-selective sensor,
wherein a second sensor is a thermal conductivity sensor and is provided to detect the thermal conductivity of the gas taken in, and a signal-receiving switch for switching the first sensor to a blind mode when a total pressure is above a limit value, the first sensor covering a low total pressure range and the second sensor covering a high total pressure range.

9. The leak detector of claim 8 , wherein a valve is arranged upstream of the first sensor in a gas flow of gas taken in, said valve being switched by the signal-receiving switch to a closed state in order to realize the blind mode.

10. The leak detector of claim 8 , wherein the first sensor comprises a heatable, selectively gas-permeable membrane, and heating the membrane is deactivated in order to realize the blind mode.

11. The leak detector of claim 8 , wherein a sniffer probe is provided for taking in gas from the atmosphere, and the first sensor is included in a measuring conduit and the second sensor is included in an intake conduit, the intake conduit leading directly from the sniffer probe to the vacuum pump device and carrying a higher flow rate than the measuring conduit, so as to increase distance sensitivity.

12. The leak detector of claim 8 , wherein the second sensor is arranged at a position where a constant total pressure prevails that approximates atmospheric pressure.

13. The leak detector of claim 8 , further comprising a bypass conduit including valves controlled by the signal-receiving switch.

14. The leak detector of claim 12 , wherein the second sensor is arranged in an intake conduit or at an air outlet of the leak detector.

15. A leak detector with a vacuum pump device through which gas is taken in, and a first sensor for detecting at least one gas component in the gas taken in, the first sensor is a saturable gas-selective sensor,
wherein a second sensor is a thermal conductivity sensor and is provided to detect the thermal conductivity of the gas taken in, and a switching valve for switching the first sensor to a blind mode when a total pressure is above a limit value, the first sensor covering a low total pressure range and the second sensor covering a high total pressure range.

16. The leak detector of claim 15 , wherein the switching valve is arranged upstream of the first sensor in a gas flow of gas taken in, said valve switching to a closed state in order to realize the blind mode.

17. The leak detector of claim 15 , wherein a sniffer probe is provided for taking in gas from the atmosphere, and the first sensor is included in a measuring conduit and the second sensor is included in an intake conduit, the intake conduit leading directly from the sniffer probe to the vacuum pump device and carrying a higher flow rate than the measuring conduit, so as to increase distance sensitivity.

18. The leak detector of claim 15 , wherein the second sensor is arranged at a position where a constant total pressure prevails that approximates atmospheric pressure.

19. The leak detector of claim 15 , further comprising a bypass conduit including the switching valve.

20. The leak detector of claim 18 , wherein the second sensor is arranged in an intake conduit or at an air outlet of the leak detector.

Assignees

• Inficon Gmbh

Inventors

• Wetzig Daniel
• Dalton Scott
• Hoffmann Daniel
• Jackson Jr Walwyn

Classifications

• G01N33/0009 Primary

  General constructional details of gas analysers, e.g. portable test equipment (devices for withdrawing samples in the gaseous state G01N1/22) · CPC title

• G01N33/0032

  using two or more different physical functioning modes · CPC title

• G01M3/002

  by using thermal means · CPC title

• G01N25/20

  by investigating the development of heat, i.e. calorimetry, e.g. by measuring specific heat, by measuring thermal conductivity (calorimeters per se G01K) · CPC title

• G01M3/205

  Accessories or associated equipment; Pump constructions · CPC title