Tracer Gas Leak Detection (Hydrogen, Helium, CO2)

Tracer Gas Leak Detection (Hydrogen, Helium, CO2)

Tracer gas leak detection, utilizing gases such as hydrogen, helium, or carbon dioxide, has emerged as a powerful tool in discovering leaks for equipment, systems and underground pipelines. This non-invasive method allows technicians to efficiently and accurately locate leaks by introducing a harmless, detectable gas using a tracer gas leak detector. As the gas escapes it can be detected using sensitive tracer gas leak detectors. In this article, we will explore tracer gas leak detection and the gas leak detectors used to detect the tracer gas.

What is a Tracer Gas Leak Detector?

A tracer gas leak detector is a sensitive gas analyzer that is able to detect low concentrations of tracer gas. Tracer gas leak detectors are also called tracer gas sniffers, tracer analyzers, tracer gas testers, tracer leak detectors and tracer leak sniffers. These tracer gas leak detectors need to be very sensitive as tracer gas analyzers are used for leak detection purposes where the concentration of gas is in the ppm or ppb gas concentration. Therefore, a very low detection limit and high sensitivity is paramount a trace gas leak analyzer.

What is a Tracer Gas?

Common tracer gases used in various industries for leak detection include hydrogen, helium, carbon dioxide and SF6. Tracer gas is sold by most gas companies. For example, for hydrogen compressed gas, it is sold as 5% hydrogen and 95% nitrogen.

List of Tracer Gas Leak Detectors

What is Tracer Gas Leak Detection in Underground Pipes?

Tracer gas leak detection, sometimes called tracer gas leak testing, is a method used to identify and locate leaks in underground pipes. It involves introducing (with pressure) a harmless, detectable gas (such as helium or hydrogen) into the pipe system. The gas escapes through any leaks present and rises to the surface. A gas leak analyzer is then used to detect the presence of the tracer gas above ground by walking slowly and scanning the surface. By mapping the concentrations of the gas, technicians can pinpoint the exact location of the leak, allowing for targeted repairs of underground piping.


What is Tracer Gas Leak Detection in Vacuum Chambers

Tracer gas leak detection is a nondestructive method for detecting gas leaks. Tracer gases are novel as they are made up of small molecules that when used will find the smallest leak sites and penetrate through the smallest leak that may be present. Examples include helium, carbon dioxide and hydrogen. The tracer gas molecules are also chosen so that they can be detected easily with a gas analyzer. In addition, all tracer gases should be non-explosive, non-destructive and safe to use. The below image shows a vacuum chamber filled with tracer gas. Since the tracer gas molecules are small, they will leak easier than molecules found in air and can be detected by a tracer gas analyzer.

What is a Hydrogen Tracer Gas Leak Detector?

A hydrogen tracer gas leak detector is a tool that locates leaks in various systems, chambers, underground pipeline and tubing. Hydrogen, with its small molecular size and low background concentration, is an ideal tracer gas for leak detection applications. Hydrogen is the most popular tracer gas for instrumentation and underground piping leak detection. It is taking over from helium, since helium is not readily available and is becoming expensive. 

What is a Helium Tracer Gas Leak Detector?

A helium tracer gas leak detector is a analyzer used to locate leaks in various systems by detecting the helium gas leaks. Helium makes an excellent tracer gas as it is inert, non-toxic, and having a low natural background concentration. However, it is not very popular since it is becoming expensive and it is a scarce resource. Most helium tracer gas leak detectors employ thermal conductivity to measure helium concentrations. 

What is a CO2 Tracer Gas Leak Detector?

A CO2 tracer gas leak detector is a device used to identify and locate leaks in various systems by detecting the presence of carbon dioxide gas. CO2 is an effective tracer gas due to its safety, availability, and ease of detection. A CO2 tracer gas leak detector employs infrared spectroscopy called NDIR to measure CO2 concentrations. By monitoring CO2 levels, the detector can pinpoint leak locations.

What are the detection limits of trace gas analyzers?

Detection limits of trace gas analyzers vary depending on the type of analyzer and the target gas. Modern tracer gas leak detectors can detect gases at parts-per-million (ppm).

Difference between Hydrogen and Helium Tracer Gas?

Hydrogen and helium are both used as tracer gases for leak detection, but they have distinct properties. Hydrogen is flammable, making it riskier to use, while helium is inert and non-flammable. Helium has a lower background concentration in the atmosphere, making it easier to detect leaks with higher sensitivity.

Requirement Helium Hydrogen
Low ambient concentration 5 ppm in air ≥ 0.5 ppm in air
Sensitivity using Handheld Analyzer? 0.1% 1ppm
Highly selective sensor technology

Thermal Conductivity

(may be cross sensitivity to other inert light gases)

Environmentally friendly Noble gas, naturally in air, no green house potential Naturally in air, no green house potential
Affordable Medium gas cost. Scarce resource. Low gas cost
Safe Inert, non flammable, non explosive Only in gas mixtures below lower explosion limit of 4%

    Tracer Gas Leak Detection for Water Leaks

    Tracer gas leak detection is an effective method for locating water leaks in underground pipes and other hidden systems. By introducing a tracer gas, such as helium or hydrogen, into the water system and using sensitive detectors to scan the area, technicians can pinpoint the exact location of the leak. This non-invasive technique saves time and money by avoiding extensive excavation and minimizing water loss. It is particularly useful for detecting leaks in large, complex water networks.

    Tracer Gas Leak Detection for Vacuum Leaks

    Tracer gas leak detection is a reliable method for identifying vacuum leaks in various systems, such as vacuum chambers, packaging lines, and refrigeration units. The process involves introducing a tracer gas, typically helium or hydrogen, into the system under vacuum and using specialized detectors to locate the leak points. This technique is highly sensitive and can detect even the smallest leaks, ensuring the integrity of the vacuum system and preventing contamination or performance issues.

    Tracer Gas Leak Detection for A/C Leaks

    Tracer gas leak detection is a precise method for finding leaks in air conditioning systems. By introducing a safe, inert gas like helium or nitrogen into the system, technicians can use sensitive detectors to locate the exact leak points, saving time and money on repairs while maintaining A/C efficiency.

    Tracer Gas Leak Applications

    Oil and gas pipeline leak detection

    Tracer gases are used to identify leaks in underground or subsea pipelines, minimizing product loss and environmental damage.

    Industrial process equipment leak testing

    Tracer gas leak detection is used to locate leaks in valves, fittings, and seals in industrial plants, refineries, and chemical facilities.

    Refrigeration and air conditioning system leak detection

    Tracer gases, such as refrigerants or helium, are used to pinpoint leaks in refrigeration and HVAC systems, improving efficiency and reducing refrigerant emissions.

    Underground storage tank leak detection

    Tracer gas testing is used to verify the integrity of underground storage tanks and detect leaks that could contaminate soil or groundwater.

    Building envelope leak detection

    Tracer gases are used to identify air leaks in building envelopes, helping to improve energy efficiency and indoor air quality.

    Automotive and aerospace manufacturing leak testing

    Tracer gas leak detection is used to ensure the integrity of fuel systems, air conditioning units, and other critical components in vehicles and aircraft.

    Power plant and boiler leak detection

    Tracer gases are used to locate leaks in heat exchangers, condensers, and other components of power generation systems.

    Wind turbine blade leak detection

    Tracer gases are used to identify leaks in wind turbine blades, which can lead to reduced performance and structural damage if left undetected.

    About The Author

    Dr. Kos Galatsis ("Dr.Koz") is the President of FORENSICS DETECTORS where the company operates from the scenic Palos Verdes Peninsula in Los Angeles, California. He is a subject matter expert on gas sensor technology, gas detectors, gas meters, and gas analyzers. He has been designing, building, manufacturing, and testing toxic gas detection systems for over 20 years.

    gas detector expert

    Every day is a blessing for Dr. Koz. He loves to help customers solve their unique problems. Dr. Koz also loves spending time with his wife and his three children going to the beach, grilling burgers, and enjoying the outdoors.

    Read more about Forensics Detectors here.

    Phone: +1 424-341-3886