Leak Detection using Hydrogen

In pipeline systems in which the medium cannot be directly detected or when checking for leak sites using the electro-acoustic method fails, the tracer gas technique is a favourable alternative.

The low amount of hydrogen (just 5%) means that this method is absolutely safe: Thanks to the use of nitrogen as the carrier gas, the gas is incombustible. It is non-toxic, and therefore also permitted for use in drinking water networks, as well as non-corrosive.

Tracer gas is cheap and easy to buy from technical gas or welding gas dealers. It is also environmentally-neutral and permeates all cover layers such as asphalt, concrete and other seal coats. Tracer gas always looks for the shortest route from the leak site to the surface.

The VARIOTEC 460 Tracergas is a Hermann Sewerin (Germany) product that is perfectly designed for this process. There are two sensors available for the following four applications above ground inspection, measuring in bar holes, inspection of household installations, gas measurement.

The gas-sensitive semiconductor sensor optimised specifically for this method of measurement is responsible for above ground inspection and inspection of household installations. Due to this specialisation, it features very low cross sensitivity to other gases such as methane and minimal cross sensitivity to moisture. Indication errors that frequently occur with other devices when transitioning from dry to moist ground are thus avoided with the VARIOTEC 460 Tracergas .

A thermal conductivity sensor performs the measuring in bar holes and gas measuring. The expanded measuring range up to 100 % vol. hydrogen enables higher concentration measurements in the bore hole for probes and thus more accurate pinpointing of the leak. In addition, this expanded measuring range means that additional tasks may also be solved.

As a member of the current SEWERIN line of devices, the entire range of accessories is available for the VARIOTEC 460 Tracergas. For example, the new D80 bell probe optimises the measuring system with the response time in mind.

As all current generation SEWERIN devices, the VARIOTEC 460 Tracergas is also operated using menu keys and a jog dial with menu navigation. A large, backlit display enables fatigue-proof reading of measured values.

The measurements can be conveniently stored with remarks and are available at any time for further processing on a PC via the USB port. The internal memory features 8MB of capacity, providing ample storage for large data volume.

The four replaceable NiMH rechargeable batteries or disposable alkaline batteries enable a minimum of 8 hours of operating time. Depending on their capacity, the rechargeable batteries can be fully charged and ready to use again within 3 hours.

The combination of an overall weight of about 1000 g, depending on the features, and the carrying gear, provides the highest possible degree of comfort to the user. The combined carrying and stand supporting bracket also facilitates transport and stationary work.