A gas that has been used to create electricity and fuel the onboard energy needs of the space shuttle and whose applications may someday fuel cars, trucks and remote power stations, has found a more down-to-earth use today.

The new QH2000 leak detector from iTiQualitek Inc. (Billerica, MA) uses hydrogen for detecting leaks and seal integrity. It uses a tracer gas that is composed of 95% nitrogen and 5% hydrogen. The 5% mixture is classified as nonflammable according to ISO 10156, and hydrogen is environmentally friendly according to the ISO 14001 standard.

The unit has a leak rate sensitivity of 0.5 parts per million and is sensitive only to hydrogen. Hydrogen, the lightest of all gases, spreads quicker in a given volume. It finds and passes through a leak faster, says Dave Morris, president of iTiQualitek.

The tracer gas is a nonflammable, noncorrosive mixture. Problems with background interference are minimized because hydrogen gas dissipates quicker than other gases. In addition, hydrogen molecules do not stick to surfaces as easily as helium and other tracer gases. This, combined with the background compensation of the QH2000, helps ensure that background contamination is rarely a problem.

To locate a leak, the diluted hydrogen is simply injected into the test object, and then a hand probe connected to the hydrogen leak detector is used to search for leaks. The detector alerts the operator with an audio signal that increases in intensity as the probe approaches the point of the leak. In the analysis mode, a digital readout indicates the magnitude of the leak.

Applications for the QH2000 are numerous. They include finding leaks in systems where pressure decay techniques cannot provide the needed accuracy, or the location of the leak must be ascertained. Some examples are leaks in refrigeration coils, heat exchangers, automotive parts, compressors and medical containers.

The unit features digital technology and does not require factory calibration. User calibration can be performed using reference gas with a known concentration. It is entirely electronic and has no pumps, valves or other items that require maintenance. At 10 by 6 ?inches, it is transportable and takes 1 minute to warm-up. It can be fitted with a protective sensor cover that allows leak detection on wet objects and is suitable for factory environments with a standard probe.


For more information on the H2000 leak detector, contact:

iTi Qualitek Inc.

13 Alexander Rd., Suite 2B

Billerica, MA 01821

(978) 670-1113

Fax: (978) 670-1114


[email protected]


  • It is sensitive only to hydrogen. It is insensitive to other gases.
  • Hydrogen is the lightest of all gases and spreads quickly in a given volume.
  • It has a gas mixture of 95% nitrogen and 5% hydrogen. The 5% mixture is classified as nonflammable according to ISO 10156.