Best Hydrogen Gas Detectors (Expert Analysis)
A hydrogen gas detector senses hydrogen (H2) concentration in the air. These analyzers are used for personal protection in hazardous gas environments. They are also found in industrial settings, battery storage centers, and hydrogen fuel cell facilities. Hydrogen is an important alternative source of energy storage, but can become dangerous if a leak occurs and accumulates indoors.
How Is Hydrogen (H2) Gas Detected?
Hydrogen is detected using a measuring instrument known as a hydrogen gas detector. These devices are specific to hydrogen gas. Hydrogen gas detectors are composed of electronics and an H2 sensor.
The gas sensor converts the detected hydrogen gas concentration to an electronic signal for analysis by the onboard microprocessor. From there, the processor outputs the reading to the display. If the measured amount of H2 exceeds the pre-set values, alarms will be triggered to warn the user. Other functions, such as instructing a relay to switch on a fan or ventilation system, are also common.
What Is a Portable Hydrogen Gas Detector?
A portable hydrogen gas detector is an instrument used to analyze the concentration of hydrogen in the air. These small gas detectors have a long-lasting battery, large screen that displays the hydrogen levels, and a belt clip to connect to clothing. The devices also have LED, vibration, and buzzer alarms.
A hydrogen gas detector is sometimes called an H2 monitor, a hydrogen sniffer, a hydrogen analyzer, or hydrogen gas tester. These names all refer to a hydrogen gas detector.
What Does a Hydrogen Detector Measure?
A hydrogen gas detector senses hydrogen (H2) in the air and displays the levels in parts per million (ppm) concentration.
While most hydrogen gas detectors detect low ppm levels (0 - 1000 ppm), others are designed to measure higher level concentrations in %LEL.
What Is Hydrogen Gas?
Hydrogen has the chemical symbol H2. It is a very light gas, a physically small compound, and becomes highly flammable at concentrations greater than 4%.
Because it is a very useful gas, hydrogen production has tripled since 1975. The growth of hydrogen gas has been fueled by its use in the semiconductor, refining, and renewable energy industries. Its growth has also resulted in an increased demand for gas detection instrumentation.
Hydrogen is also used in refining gas products, energy storage, as a coolant in power generation, and the chemical industry, especially in making ammonia (NH3).
Interestingly enough, hydrogen gas does not interact with the body and is non-toxic when inhaled. However, it can act as an asphyxiant at a high concentrations where it may displace oxygen levels.
Can I Smell Hydrogen Gas?
No, hydrogen gas is not an aromatic gas and cannot be detected by the human nose.
What Is the Difference Between Hydrogen (H2) and Hydrogen Sulfide (H2S) Gas?
There is a big difference.
Although their chemical symbols are very similar, H2 and H2S are two completely different gases. Click here for more information on Hydrogen Sulfide Gas Detectors.
What Are the Different Types of Hydrogen Gas Detectors?
Hydrogen Gas Detector for Personal Protection
The majority of hydrogen gas detectors are portable. These small, battery-powered units contain a hydrogen sensor and can be clipped to your clothes. These detectors provide continuous personal protection with LED, buzzer, and vibration alarms. Two varieties exist:
Hydrogen Gas Leak Detector
This analyzer is a combustible gas leak detector that uses a semiconducting metal oxide sensor to detect small amounts of hydrogen (ppm).
Catalytic bead pellistor (combustible) sensors are also very useful for Hydrogen Gas Leak Detection. The EX 0-100% LEL with pellistor sensor is very useful to find 100% hydrogen gas leaks. Using other sensors may poison the sensor due to the high H2 content. For example, when storing liquified H2, pin pointing hydrogen gas leaks can be challenging. A low level 0-1000ppm will work, however, may be damaged and poisoned when detector 100% hydrogen. Therefore, we recommend our EX LEL% Analyzer with built in pump configuration for this application.
Hydrogen Gas Monitor for Stationary Fixed Wall
Fixed wall-mounted units provide continuous H2 protection. These devices are perfect for indoor situations, such as a battery room or power generator area. If the H2 levels rise above a pre-set threshold, the unit will alarm and can automatically trigger the ventilation system.
How does a Hydrogen Detector work?
A hydrogen gas detector is composed of electronics and an H2 sensor. The H2 gas sensor converts the detected gas concentration to an electronic signal for analysis by the onboard microprocessor. From there, the processor outputs the reading to the display. If the H2 levels exceed the pre-set values, alarms will be triggered to warn the user.
The gas reacts with a working electrode, triggering an electrochemical redox reaction. The current generated is proportional to the detected gas level.
Semiconducting Metal Oxide Sensors
The hydrogen gas molecules interact with a film of metal oxide material, where surface redox reactions take place. A power-law relationship occurs between the hydrogen gas concentration and sensor conductivity.
Catalytic Bead Pellistor Sensors
The hydrogen gas oxidizes on the bead, changing the conductivity of the element. The resistance change is
proportional to the H2 concentration.
Is Hydrogen Gas Important for Renewable Energy? (H2 Gas Detection Role?)
By itself, H2 doesn't produce any energy but can store energy in gas or liquid form. Hydrogen is an energy supply used as a form of energy, just like a battery. Hydrogen gas is produced using fossil fuels. However, hydrogen is poised to be a critical component in the next generation of renewable energy due to its ability to store energy (like batteries, gasoline, or water in a dam).
The ultimate plan is to store renewable energy in H2 gas or liquid form. When required, hydrogen can be used with a fuel cell to produce useful electrical energy.
Gas detection in this situation is paramount. Think about all of the possible storage and distribution leaks a system may generate over a long period of time. Therefore, low cost and reliable hydrogen gas detection is essential for the next generation of renewable energy.
What Are Safe Hydrogen Gas Levels?
Various government agencies, such as OSHA, NIOSH, and ACGIH, have not made any recommendation on hydrogen gas. This is because it is non-toxic to humans.
Therefore, occupational exposure standards are are based on the flammability of hydrogen gas rather than its toxicity.
Hydrogen is a flammable and explosive gas. The U.S. Environmental Protection Agency (EPA 1988) recommends personnel to evacuate when hydrogen gas reaches 10% of the lower explosive limit. The explosive limit of hydrogen is 4,100 ppm (4.1% volume), while 10% of 4,100 ppm is 410 ppm.
What Is a Hydrogen Detector Used For?
Hydrogen is used in many applications and its uses continue to grow.
- Hydrogen Detection in Battery Rooms: Battery storage and recharging is becoming more common in both industrial and residential settings. Lead acid batteries are cost-effective and have good energy density. They are useful in mobile situations such as power forklifts, carts, and mobile machinery. In addition, they are an excellent option for power backup in critical emergency systems. When recharging lead acid batteries, hydrogen is outgassed. In poorly ventilated rooms, hydrogen accumulation happens quickly, making continuous hydrogen monitoring very important. In these cases, a wall-mounted (or ceiling-mounted) hydrogen monitor with continuous detection is recommended.
- Hydrogen Detection in Refining: Hydrogen gas is commonly used in oil refinery operations, such as hydrocracking. This is the reduction of heavy gas oils to lower molecular weight constituents. Because the equipment is complex, there is a higher possibility of leaks in confined spaces. These hazardous leaks may cause hydrogen accumulation and asphyxiation. Therefore, both wall-mounted units and personal protection handheld hydrogen detectors are recommend.
- Hydrogen in Ammonia Synthesis: Over half of the hydrogen produced is used to make ammonia (NH3) and fertilizer. Atmospheric nitrogen reacts with hydrogen to produce ammonia, the precursor to nitrogen-based fertilizers.
Can a Gas Leak Detector Be Used to Detect Hydrogen Gas?
Yes, a combustibles gas leak detector with ppm resolution can be used to detect a hydrogen gas leak - see here.
Gas leak detectors are typically calibrated to detect methane or propane. If using a gas leak detector for hydrogen detection, double-check the calibration and make sure any correcting factors are applied correctly - see here for correcting factor adjustments.
What Is the Best Hydrogen Gas Detector?
There are many hydrogen gas detectors on the market, including electrochemical (ppm) and or catalytic bead (%LEL) analyzers. The reputable brands include the following:
- Forensics Detectors Personal Hydrogen Detector
- Forensics Detectors Wall Mount for Battery Rooms
- SBS Hydrogen Gas Detector
- MSA H2 Monitors
- RKI Portable H2 Detectors
- Industrial Scientific H2 Monitors
- Draeger H2 Meters
- Sensidyne H2 Detectors
How Do I Select a Hydrogen Gas Detector?
To select the best hydrogen gas detector, follow this guide. Narrow down your selection by determining your purpose and the answers to these questions:
- Do I need it for a battery room? If so, your best bet is a wall-mounted hydrogen gas monitor.
- Do I need it for personal protection? If so, your best bet is a handheld hydrogen gas detector with alligator clip.
- Do I need a probe with the unit? Do I need to point sample to detect ab H2 gas leak?
- What is my budget and operating cost budget?
- Do I need advanced functions, such as data-logging or Bluetooth?
- Do I need specific accreditations with the monitor, such as ATEX or a NIST traceability calibration certificate?
- Do I require a belt clip for attaching to my clothes?
- Do I need after-sales support, USA headquarters, or fast calibration services?
How Long Does a Hydrogen Gas Sensor Last For?
Hydrogen detectors that incorporate electrochemical sensors last between 24 and 36 months. Analyzers that incorporate semiconducting metal oxide (ppm) or catalytic bead sensors (%LEL) function for over 5 years.
How Do I Test My Hydrogen Gas Detector?
The best way to test your hydrogen gas detector is to expose it to a known gas source. Generally referred to as bump testing, this is a good practice to perform daily, especially in personal protection applications where safety is paramount.
What Is a Hydrogen Gas Detector Bump Test?
- Bump testing is a procedure when one exposes the detector to a small amount of “blast” target gas to ensure the detector operates and alarms as programmed.
- The function of this test is to verify proper operation and build user confidence, particularly in hazardous applications.
- It is recommended to bump test when first purchased, followed by weekly tests, If using in LIFE-THREATENING and or DANGEROUS applications, bump test daily.
- Hydrogen bump test gas can be found here.
What Is Hydrogen Detector Gas Calibration?
Hydrogen gas detector calibration is the technical task of adjusting the device to a more accurate gas reading. Over time, the sensors may drift and degrade. We typically suggest calibrating your hydrogen detector every 6 to 12 months, a typical time period for gas detectors.
Gas calibration is a technical task and requires certain key pieces of equipment. This includes a calibration gas bottle, gas regulator, tubing, and calibration cap fitting. You need to confirm the calibration gas concentration and mixtures with the manufacturer. For the Forensics Detectors hydrogen gas detectors and monitors, we recommend gas calibration with H2 at 100 ppm. See hydrogen calibration gas here.
Be attentive and calibrate daily if:
- The device is used as an analytical tool where accuracy is paramount - such as research or development projects.
- The device is used in an extreme environment (temperature and humidity extremes create sensor drift).
- The user is performing an imminently dangerous or extreme application.
- Bump testing fails. In this case, you must calibrate to make sure the sensors and monitor function properly.
- The hydrogen gas detector is alarming in the fresh air where a sensor has potentially drifted past a set-point.
Calibration and bump testing are mandatory since imminent injury or death will occur if the device fails. Take it very seriously.
Also, it is prudent to have a calibration schedule that the owner or employees follow strictly. See gas calibration here.
How Do I Take Care of My Hydrogen Detector?
- Store your hydrogen gas detector at normal room temperature - about 70F with 50%RH (well within operating specifications).
- Store it away from electromagnetic or magnetic sources, such as phones.
- Store it in a clean environment with no dust or particles.
- Store away from any exhaust gas, concentrated vapors, or harsh chemicals.
- Clean the casing of your detector with a damp cloth.
- Store it in a stable place where there are no vibrations or continuous shaking.
How Do I Properly Use a Hydrogen Gas Detector?
When operating a hydrogen gas detector, there are some important tips to consider. Be smart, read your product manual, and keep these tips in mind:
- Turn ON the hydrogen gas monitor in fresh air.
- Ensure the hydrogen gas monitor is within its calibration period.
- Ensure the hydrogen gas monitor has been bump tested and validated as operational.
- Check alarm set-points. Set your alarms as desired (some units may not have adjustable alarms).
- If performing analytical measurements, keep the unit stationary. Ensure humidity and temperature are also tracked and are as constant as possible.
- If using a pump, turning the pump ON/OFF will change the pressure and may affect readings. Take data point readings when the pump is either ON/OFF for 60 seconds, so no erroneous data points are taken because of a "pressure change."
- Place your detector in the proper location. After 60 seconds, take your data (i.e., hydrogen gas concentration displayed on the digital display).
Is Hydrogen Gas Explosive?
Yes, it is. Hydrogen is flammable at concentrations from 4% to 75% in air.
Therefore, hydrogen gas has a lower explosive limit (LEL) of 4% - this means it is too lean to burn.
The upper explosive limits (UEL) is 75% - this means it is too rich to burn.
Typically, for gas detectors, 10% LEL is the first alarm for hydrogen gas. 10% of 4% = 0.4%, which translates to 4,000ppm.
For %LEL and ppm conversion, see here.
- A hydrogen (H2) gas detector senses H2 concentration in air. Hydrogen is a flammable gas with a LEL of 4% volume.
- The largest markets for hydrogen gas detectors are the refining, fertilizer, and battery storage and charging industries. Hydrogen gas detectors are used for personal protection, continuous monitoring, checking H2 accumulation, and finding leaks.
- Hydrogen gas detectors are small and cost less than $400. Follow this guide to figure out which hydrogen gas detector you need.
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.
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 having a cold beer.
Read more about Forensics Detectors here.