Best Helium Leak Detector (for Leak Detection in 2023)

Helium gas is a very light inert gas that requires gas detection. Most people are likely familiar with helium gas's function as a means to blow up balloons used in parties but helium is an important inert gas used in various industrial settings. A helium leak detector is imperative to ensure no leaks of the precious gas exists in many instruments. Often used in applications such as welding, diving, rocket propulsion, cryogenics, MRI, processing, meteorology and research & development.

Pros	Cons
Helium is special gas. It is light, small inert and a scarce gas Helium leak detectors are used to detect helium content in a gas mix or helium gas leak Helium leak detectors are useful for welding, rocket propulsion, cryogenics, MRI, meteorology and research and development	Helium gas leak detectors vary in large price scale $100s to $10,000s (depending on sensitivity) Critical to understand the application to ensure correct gas detector selection, range and lowest level of detection Difficult gas to measure, requires use of specialized thermal conductivity sensors

Best Helium Gas Analyzer?

Helium gas analyzers are used to analyze gas mixes for breathing, trimix scuba, compressed gas, industrial applications, welding, and research & development. Most helium gas analyzers detect from 0-100% helium content in air with a 0.1% resolution. A few reputable Helium Gas Analyzer options include:

• Forensics Detectors Helium Leak Detector (Purity% and Leak)
• Bacharach's He Helium Analyzer (Process Control)
• Eaton Helium Gas Analyzer (Process Control)
• Nuvair's Pro He Alarm Analyzer (Breathing Gases, Diving)
• Divesoft Helium Analyzer  (Breathing Gases, Diving)
• Analox Helium Analyzer (Breathing Gases, Diving)
• Analytical Instruments Helium Analyzer (Diving)

What is the Best Helium Leak Detector?

These analyzers are used with a probe to detect helium leaks in various equipment, vacuum equipment, spectrometers and cryogenics. Since helium is light, it is a excellent tracer gas and can penetrate leaks or compromised seals to then be detected and ultimately find a leak. Some reputable options include:

• GL Sciences Helium Leak Detector
• Ion Science Helium Gas Leak Detector
• Infinicon Helium Leak Sniffers
• Nolek Helium Sniffer
• Forensics Detectors Helium Analyzer (Generic)

Is Helium Gas Critical to MRI scanners?

Yes. Helium is used to cool the superconducting magnets in a MRI scanner to a temperature below 4,15 Kelvin (-269°C). Since helium is a very small molecule, it can leak and hence, all seals and welds must be perfect in an MRI. A helium leak detector is imperative to be used in high magnetic fields such as those found around the outside of Magnetic Resonance Imaging (MRI) scanners. 

How is Helium Gas Detected? 

Since helium is an inert gas, chemical methods to detect He gas, such as redox reaction that are used in electrochemical and semiconducting metal oxide gas sensors do not work. Therefore, the change in thermal conductivity (since it is lower in molecular weight) compared to air, is an excellent physical method used to make a helium sensor. These sensors are called thermal conductivity detector (TCD), referred to sometimes as a katharometer. Two thermal element compared normal air with the gas sample. If the sample gas has an amount of "helium" the change in conductivity as a result of the physical thermal change will be detected and translated into a useful calibrated He concentration.

What is Helium Gas?

Helium is a gaseous compound that is colorless, odorless, and tasteless. It can be isolated from natural gas when the other compounds are liquefied at a low temperature and high pressure-- the helium remains as a gas. It finds uses in welding for other metals, in rocket propulsion, in meteorology, in cryogenics, and in high-pressure breathing operations.

Is Helium Gas Hazardous?

In general, helium gas is non-toxic and inert, decreasing its risk to humans. With that said, excessive inhalation of the gas can have asphyxiation effects due to the lack of oxygen.

Why is Helium Used in Trace Gas Leak Detection?

Using helium for trace gas leak detection has many advantages. Several are outlined below:

• Helium constitutes a relatively low concentration of gaseous compounds found in the air, meaning that there is not a high degree of background gas that can affect the reading
• Helium is inert and relatively stable
• Helium is non-toxic, non-flammable, non-explosive, and relatively safe for humans unless it is inhaled in a large quantity

How to undertake a Helium Leak Test?

There are several ways of undertaking a Helium Leak test using a Helium Gas Sniffer. Once method is called the “local-sniffer (sample under pressure)” method. In this case, the chamber of concern filled with helium and a helium gas leak detector is passed around the chamber, weld areas, connectors, seals, flanges and ducts for inspection and to see if any He is leaking. This “sniffed” gas is passed to a Helium sensor or mass spectrometer to record any elevated concentrations.

What is a Helium Mass Spectrometer Leak Detector?

The most expensive and most sensitive helium gas detectors function based on sector field mass spectrometry. Helium gets ionized in a vacuum where its ions are subsequently accelerated and separated in a magnetic field. The current generated from the ions is converted to electric current and that is what is displayed as the detection value. This is because the current generated is directly proportional to the concentration of helium.

What is a Helium Gas Detector?

A helium gas detector is a measurement device used to detect the presence of helium in the air. It is frequently referred to as a helium gas sniffer, helium gas analyzer or helium monitor. These are digital instruments that have been calibrated to a known supply and concentration of helium and present the user usually with %volume of helium gas in the air.

How to Select a Helium Gas Detector?

When selecting a helium gas detector the first question that should be asked is "What is the application". If the application is for diving, breathing gas, process control or determining the He gas concentration in air, most likely a generic Helium Gas Analyzer will be suitable. Then questions such as features, size, power and other functional attributes will be important. If on the other hand, one requires a He analyzer for gas leak detection, then one must focus their search on Helium Gas leak Detectors.

Who Uses a Helium Gas Leak Detector?

Certain individuals in specialized industries may find a use for helium gas leak detectors. The largest "mainstream" market for helium analyzer is the diving and scuba market, where helium is part of a trimix breathing gas mix. Confirming the He gas concentration in the trimix is imperative.

Does Helium Leak Out of Tanks?

Helium tanks are often used to transport helium gas from one location to another. In these tanks, the helium should not leak out unless the valve has not been properly closed. As such, it is imperative to make sure to tighten the valve shut after using the helium.

What Are Some Common Methods for Helium Leak Testing a Vacuum System?

When helium leak testing in the presence of a vacuum system, there are two major methods used: integral testing and local testing.

Integral Testing

Integral testing takes place when the sample is under pressure/vacuum and is also in a vessel. The sample is either evacuated or placed into a vacuum, so it is sometimes referred to as a helium vacuum test.

Local Testing

Local testing takes place when the sample is under pressure/vacuum but is not in a vessel. The sniffed or pumped gas is passed to a mass spectrometer for a reading.

Is Helium Flammable?

No it is not. Helium is typically regarded as a fairly safe gas. In fact, it is frequently used to fill balloons at parties and events.

Final Words

• Helium gas detectors are used to detect helium content in a gas mix, gas flow or often used to detect a helium gas leak (MRI scanners use helium to cool down their superconducting magnets)
• Helium gas detectors may be useful in application such as welding, rocket propulsion, cryogenics, MRI, meteorology and research and development
• Helium gas detectors go by a number of names including helium gas leak detectors, helium gas sniffers, helium gas analyzers, and mass spectrometer leak detector

About the Author

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.