Top Features of H2S Gas Sensors

Arguably the most toxic gas found in industrial environments, hydrogen sulfide can be deadly in only a matter of minutes or even seconds. Due to the many dangers associated with this type of gas, companies in the oil and gas industry, as well as other manufacturing industries, have invested in hydrogen sulfide gas detectors in an effort to improve workplace safety and protect employees. Choose a quality hydrogen sulfide detector by looking out for these key features.

1. Programmable relays
2. Legacy control systems
3. Real-time monitoring
4. Customizable systems

1) Programmable Relays

Since hydrogen sulphide is so deadly, it’s crucial sensors installed in a facility are able to detect the smallest amounts of gas as quickly as possible. Programmable relays allow for early warning of hazards by turning on audible and visual alarming devices to notify employees in the vicinity of the gas detector.  This can prove vital in halting a potentially dangerous event from happening.

2) Legacy Control Systems

The flexibility of the H2S gas detector is crucial. Flexibility is determined by the types of outputs the detector is equipped with.  Some systems are older and therefore the detector needs to be adaptable into the older systems. Therefore the programmable relays, 4-20mA or RS-485 Modbus options are crucial.  

3) Real-Time Monitoring

When installing H2S sensors, one of the best safety features they possess is the ability to perform real-time monitoring. As the sensors have become more advanced technologically, they can provide safety engineers and technicians with data as it occurs, allowing for quick decisions in the event of an emergency. H2S detectors use built-in concentration graphs to display current data, giving on-site technicians and safety personnel the ability to accurately assess situations.

4) Customizable Systems

With technology improving continually in the area of hydrogen sulfide detection, gas detection systems are now able to be customized depending on the work environment, data systems, and gas concentrations. When choosing a hydrogen sulfide detector, it’s important to look at the bigger picture and how it fits into the entire gas detection system. Because there are a number of factors that make your environment unique, having a detector with different input/output options will help you stay one step ahead of danger.

Choose GDS Corporation

We’re proud to offer a number of top-of-the-line solutions for detecting H2S levels in industrial settings such as oilrigs or wastewater treatment plants. With the technology to detect hydrogen sulfide fast and accurately, you can rest assured that you and your team will be warned of hazardous conditions. 

Get in touch with our team to learn which hydrogen sulfide detector is best for your work environment.

What Is Hydrogen Sulfide & Where Can It Be Found?

Hydrogen sulfide is a toxic gas that can be emitted during the drilling or extraction of natural gas. It is also present when bacteria in waste or organic materials break down due to an absence of oxygen. Because even the smallest concentrations can cause side effects, it is extremely lethal in confined spaces, low-lying areas, or spaces with poor ventilation. 

Here are three dangers of H2S gas worth considering:

1. It’s colorless
2. It can be life-threatening
3. It can be highly explosive

1) It’s Colorless

Although hydrogen sulfide is known for its “rotten egg” smell and often goes by the names sour gas, sewer gas, or stink damp, its danger lies in its absence of color. As a colorless gas, H2S gas can unknowingly build up in an area and reach an exposure limit that can limit your ability to smell. This reaction known as olfactory desensitization can deaden your senses, which in turn, could allow H2S gas to increase to a concentration that could lead to irreversible health effects.

2) It Can Be Life-Threatening

Like most toxic gases, H2S exposure can be gravely dangerous for the health of your workers. Those who operate machinery or work in close proximity to hydrogen sulfide gas should be educated about the symptoms when the gas is present. According to the Occupational Health and Safety Administration, H2S gas is one of the major causes of workplace injuries.

Even moderate levels of exposure to hydrogen sulfide can result in fatigue, headaches, loss of balance, and vomiting. A person exposed to a concentration over 50ppm may experience severe side effects while being exposed to 100ppm or above can mean immediate death. H2S is more dangerous than other gases because a person may lose their sense of smell and wouldn’t be able to determine if the hazard was still present. This false sense of safety tends to lead people to lower their defenses and not exit the environment thinking the gas is no longer present.

3) It Can Be Highly Explosive

H2S gas, in high enough concentration, can also be explosive. H2S is both flammable and explosive over a wide range of concentrations so, even the smallest ignition sources such as cigarettes, pipes, or even matches can create a dangerous situation.

Choose GDS Corp

Does your facility produce hydrogen sulfide gas as a by-product or use hydrogen sulfide gas on a regular basis? Given the toxic nature of the gas, it is important to educate workers about the nature of this deadly gas and establish a safety protocol that you can follow. With GDS Corp, you can trust that your workers will have the solution needed to guard against these hazardous characteristics of hydrogen sulfide.

Contact our team for a hydrogen sulfide gas detector customized to your specific needs.

What Do H2S Monitors Detect?

Often referred to as the “rotten egg” gas, hydrogen sulfide, or H2S, is extremely toxic and flammable. If the gas concentration of H2S isn’t kept under control, anyone who inhales it will experience a myriad of harmful health effects ranging from a headache to possible death. An H2S monitor not only keeps a tab on current gas levels in your absence but will signal alerts in the case of a gas leak when you can’t rely on your sense of smell.

The following industries either use or experience high levels of hydrogen sulfide in their daily operations. Discover why these industries could benefit from having an H2S monitoring system.

1. Manufacturing factories
2. Refineries
3. Food processing
4. Drainage and sewage areas
5. Mining processes

1) Manufacturing Factories

One of the main uses of hydrogen sulfide is in the production of sulfuric acid and elemental sulfur. Acting as a chemical reagent to prepare those chemicals, products such as pesticides, leather, and pharmaceutical drugs are created. Having a gas detector that is specifically configured to measure the target gas of hydrogen sulfide would not only reduce accidents but help employees maintain equipment around the factory.

2) Refineries

Oil refineries that are working to process large amounts of oil use hydrogen gas to remove sulfur from petroleum. This is a mass process that requires large amounts of H2S gases and may involve different combustible gases. Oil and gas companies can use a detection system to not only target the levels of H2S in their vicinity but if necessary, multiple channels can be set up to monitor multiple gases.

3) Food Processing Facilities

Used in most pesticide applications, hydrogen sulfide has proven to be a strong ingredient in protecting perishable foods. A recent study showed that H2S helped not only delay ripening but also inhibited certain fungal growth. For food processing facilities, having an H2S gas detector is crucial for the safety of employees who may be exposed for extended periods of time.

4) Drainage and Sewage Areas

Although it can be hard to control levels of H2S in drainage or sewage areas because it is being released as a byproduct, the confined space of manholes or sewers is the greatest cause of concern. Hydrogen sulfide is heavier than air, which means that it will likely settle in areas where workers may find little room to escape. Having a detection system with an H2S gas sensor helps those inside the confined areas as well as those on the outside standing by for an emergency.

5) Mining Processes

Known as stinkdamp in the mining industry, hydrogen sulfide is often found in trace amounts in mines. Depending on the surrounding conditions, even small amounts of H2S can be lethal in mining applications. H2S is produced as a byproduct of the decomposition of iron pyrites due to the presence of water and how they interact. For miners, having a toxic gas detection system installed on your equipment is crucial for maintaining safe working conditions.

Reliable Hydrogen Sulfide Gas Detection

While you may work with a number of different chemicals on a regular basis, having a single-gas monitoring system will greatly reduce your response time. GDS Corp is proud to offer a number of different H2S gas detection systems for your benefit. Built to withstand conditions found in both industrial and commercial environments, our products are available to meet your industry’s specific requirements.

Contact our sales team for a solution that fits your day-to-day operations.

A hydrogen sulfide (H2S) gas detector is often part of a monitoring system designed to detect high levels of hydrogen sulfide in ambient air. Hydrogen sulfide detectors can also be used in sample draw monitors to remotely measure H2S gas in confined spaces, and with the proper equipment can be used to monitor the level of H2S in streams of natural gas. Overall, the hydrogen sulfide (H2S) gas monitor is an efficient way to monitor the gas concentrations in your vicinity.

How Does an H2S Detector Work?

Hydrogen sulfide gas detectors primarily use electrochemical sensors to detect and measure parts-per-billion (‘ppb’) and parts-per-million (“ppm”) levels of H2S gas. These sensors depend on a highly reliable electrochemical reaction that occurs when H2S gas combines with specific materials used in the sensor. This reaction creates a tiny electrical current that is amplified and measured by the electronics in the gas detector. These industrial quality H2S detectors can help make sure the  H2S concentration level stays below the limit required by The Occupational Safety and Health Administration (OSHA). 

Depending on the environment, the Permissible Exposure Limits (PEL) for H2S gas are:

• General Industry Ceiling Limit: 20 ppm
• General Industry Peak Limit: 50 ppm (up to 10 minutes if no other exposure during shift)
• Construction 8-hour Limit: 10 ppm
• Shipyard 8-hour limit: 10 ppm

Types of Hydrogen Sulfide Detectors

GDS Corp offers a number of gas detectors that can be programmed to monitor hydrogen sulfide exclusively, such as:

• GASMAX CX Gas Monitor – Single or dual channel gas monitor certified for hazardous areas where gas readings need to be transmitted in real-time
• GASMAX EC Gas Monitor – Loop-powered gas detector for all toxic gases; certified for Explosion Proof or Intrinsically Safe installations
• GDS-58NXP – Single or dual channel sample draw gas monitor designed to measure gas samples pulled from remote locations up to 100 feet away
• GDS-49 Gas Sensor  – Loop-powered stand-alone gas sensor transmitter with replaceable sensors for any toxic gas
• GDS-68XP or GDS-68SXP Process Monitor – Process gas monitor used to measure hydrogen sulfide or mercaptans in low oxygen streams such as gas pipelines.

Pro Tip: In addition to your health, don’t neglect to protect your equipment from hydrogen sulfide’s flammable nature in very high concentrations. Install a flame detector to ward off any potential fires.

Reliable Gas Detection Systems

Does your waste facility or manufacturing process have a gas detection system installed? While hydrogen sulfide is typically characterized by its rotten egg smell, you can’t rely on your senses alone since high levels of H2S cannot be detected by smell. Don’t ignore the hazardous effects of H2S in your vicinity; install an H2S gas detector you and your team can rely on.

Not sure which gas detector to choose? Connect with our gas detection professionals to find the best solution for your facility.

Do you regularly work in processes that produce hydrogen sulfide gas? While the gas has been found in homes as a result of plumbing leaks, there is a greater chance for overexposure in workplaces and industrial settings. Depending on your industry, high levels of hydrogen sulfide could cause injury or death if not properly detected. Protect the health of your workers by understanding the dangers and signs of H2S poisoning and by installing gas detectors that can provide early warnings.

Dangerous Effects of Hydrogen Sulfide

Exposure to hydrogen sulfide usually occurs through inhalation, but occasionally can cause skin or eye irritation. Due to the invisible nature of gas, the spread of hydrogen sulfide has no bounds. While its foul-smell can warn of a hazardous leak, your sense of smell isn’t reliable. High concentrations of H2S in the air can actually corrupt your senses from working (olfactory desensitization), which could put your health at grave risk.

The dangerous nature of hydrogen sulfide is reflected in its ability to affect every organ in your body. According to the Agency for Toxic Substances & Disease Registry (ASTDR), prolonged exposure could cause eye irritation, fluid in the lungs, and eventual loss of consciousness. Your prognosis is usually determined by the amount of H2S that you were exposed to, especially if you’re wondering about your long term outcome.

Pro Tip:  We have a selection of gas detectors that can be set up as hydrogen sulfide monitors for your facility’s detection system.

Symptoms of Exposure

Depending on the length of time and amount of hydrogen sulfide exposure, your symptoms will range in severity. To enable detection systems to monitor levels of exposure, OSHA has set a permissible exposure limit for H2S gas of 10 ppm over an 8-hour period. Anything higher than that could cause extensive injuries or death.

Low Concentrations (10 ppm or less)

• Burning eyes
• Coughing
• Shortness of breath
• Headache
• Nausea

Moderate Concentrations

• Eye irritation
• Fluid in lungs
• Difficulty breathing
• Insomnia

High Concentrations (100 ppm or greater)

• Tremors
• Convulsions
• Rapid unconsciousness
• Coma
• Death

Hydrogen Sulfide Poisoning: What To Do

If you’ve been exposed to hydrogen sulfide, the most important thing to do is to not panic. While it is a very toxic gas, there might be time before you start experiencing symptoms. For eye or skin exposure, it’s important to wash immediately and remove all of your clothing. If you’ve inhaled hydrogen sulfide, try to get to fresh air and away from the contaminated area.

No matter the situation, it is crucial for you to get to a hospital immediately, even if you’re exposed to low concentrations. While headache or nausea might see like minimal concerns, those symptoms could be your first warning of a nervous system failure.

Protect Your Buildings from H2S Gas

In workplaces where hydrogen sulfide gas is produced, the effects of exposure can cause bodily harm as well as damage to your equipment. Due to the flammable nature of H2S, it’s critical for wastewater facilities and industrial manufacturers to have a reliable gas detector in place at all times.

Does your business have an H2S gas monitor? Connect with our team to choose the best detection system for your area.

1. Put On Your Gear

If you’re not already wearing your gas mask but have one available and nearby, put it on. Now is the time to use that training you gave up overtime to go get, so use it. Pull your straps down tight, and breathe like you were taught. After yours is on, help anyone who is struggling. Your mask will help keep you safe while you clear the area. Requirements for having the masks vary from location to location depending the environment, so if you don’t have one available, don’t panic, just proceed to the next step.

2. Get Upwind

If you’re working in an area with the possibility of H2S release, there should be flags or wind socks on the work site to show you which direction the wind is blowing. Head in the opposite direction immediately. If you can’t see the wind sock, toss some dirt or leaves into the air, or look at the trees. The wind can blow and concentrate the H2S into valleys or stands of trees, so the direction you go is important. If a designated gathering area, or “muster site” is indicated downwind, go there. This is the easiest and most effective way to avoid H2S inhalation or poisoning.

3. Count Heads

It might not be your stated job to do the final “head count”, but safety is everyone’s business. Someone could have succumbed to H2S before clearing the pad, or have a faulty hydrogen sulfide monitor. If you saw someone at the job location but do not see them at the muster site, make it known. Do not attempt to get them from a dangerous area, and don’t go back into the gas to locate someone unless you are trained and have the proper equipment. H2S is no joke, and has taken down big, tough, strong men and women who thought they could handle “just a minute”.

4. Make the Calls

Calling the proper civil authorities ensures local residents and landowners are notified of the issue. Necessary evacuations can be made quickly to avoid injury. This action protects everyone, including your company and job, so again, their safety is your business. Once necessary emergency authorities are notified, make the calls to the company who owns the site. Numbers should be posted at both the joh location and muster site. If not, call your boss or the company “safety man”.

While it is important to act quickly in an H2S emergency, taking these measures will help keep you out of harm’s way and within regulatory compliance. Finally, always maintain your monitor and replace it as necessary. It knows before you do when H2S levels are too high.

Portability

Because workers in the oil and gas industry as well as other industries spend much of their workday in confined spaces, it’s become necessary to offer them as much protection as possible from gases and chemicals. As a result, many workers today now carry portable benzene monitors from one area to another, allowing them to quickly monitor an area and assess if the situation is safe for them to perform their job. Since many workers on offshore rigs spend many hours each day in confined spaces, portable monitors have become much more prevalent in recent years.

Constant Monitoring

One of the most significant advances in fixed benzene detectors over the past decade has been the ability to provide constant monitoring of facilities that has become much more accurate and reliable. Very useful in numerous types of harsh working environments, constant monitoring allows for the most up-to-date information for workers, allowing them to be aware of potentially serious situations well in advance.

Real-Time Monitoring

In situations where potential danger may exist, it’s vital that employees be able to monitor their surroundings in real-time. By having benzene sensors that allow this to happen, current levels of benzene and other gases and chemicals will always be available, letting workers as well as management monitor the situation and be able to prepare for emergencies if necessary. This can be accomplished not only by using wireless technology to send real-time information to monitoring centers, but also by using sensors and monitors that have multiple alarm systems such as flashing lights, sirens, and horns.

Reduction of Maintenance

One of the biggest advantages of these sensors is the reduction of maintenance tasks, thanks largely to advances in technology that have led to greater accuracy and reliability. Using a combination of data analytics, process controls, and risk mitigation, these sensors have made tremendous strides in providing readings which are more accurate and reliable than ever before. Along with this, less maintenance also leads to less money being spent to replace monitors, allowing companies to spend that money on equipment or employee training.

Consult with GDS

If you have additional questions regarding how H2S sensors work and their ability to provide accurate readings, contact GDS Corporation and speak with a trained consultant who has many years of knowledge and experience in these and related matters.

Installation Procedures

As with any workplace equipment, it’s vital that an H2S gas sensor be properly installed. In many situations, an H2S microsensor is installed in confined spaces to alert workers to potentially dangerous situations. Since workers in these areas often have little warning when dangerous situations arise, an H2S gas detector can allow workers the time they will need to evacuate an area before a fire or explosion occurs.

Real-Time Monitoring

To detect hydrogen sulfide gas, detectors must be able to monitor gas levels in real-time and send the data to supervisory and safety personnel who are located at the workplace and at monitoring locations miles away. By doing so, engineers can carefully monitor the ambient air and process gas stream, enabling them to remotely calibrate the sensors if needed to maintain accurate and reliable data transmission.

Increased Property Damage

If a facility begins to notice increasing problems with damage to equipment and other areas of the workplace, there may be a chance hydrogen sulfide is to blame. Because it has a very adverse reaction to heat, structures and equipment can begin to corrode, which can eventually bring some operations to a halt as well as put workers at increased risk for injury. When these problems are noticed, it’s a good idea to install sensors that can measure the gas levels to determine the seriousness of the situation. However, be sure to do so at the first signs of these problems, since failing to do so could result in fires or explosions.

Portable Detectors

As the dangers from hydrogen sulfide have become more well-known in recent years, more and more companies are equipping workers with portable detectors that can be used in all work areas. However, an important point to remember is that since these detectors move from one type of environment to another, they may need to be calibrated more frequently to ensure their readings are accurate and reliable. To stay as safe as possible, safety personnel should follow OSHA guidelines for gas detector calibration, with a bump test performed daily and a calibration test performed once monthly at a minimum.

Contact GDS Corporation

Due to hydrogen sulfide being such a dangerous part of industrial workplaces, it’s crucial to have the proper detectors in place as soon as possible. To ensure your workplace has what it needs, contact GDS Corporation and speak with an experienced and knowledgeable applications engineer. By explaining your workplace and its needs, you’re sure to get the detection equipment that will keep workers and equipment safe from harm.

For these reasons, it is vital to maintain an effective network of hydrogen sulfide detectors in all areas where this gas may pose a threat. In addition, it is important to ensure that all deployed H2S sensors are operating properly. The following three events can be a warning that a hydrogen sulfide detector has either failed or is in the process of failing. By noting these events, the company can take corrective action before tragedy strikes.

False Positives Can be a Warning Sign

When a sensor starts giving a high number of false positives, it could be a sign that the mechanism itself is about to fail. This can be especially dangerous because the common response to a false positive is to determine that the alert is in error, while failing to check the sensor itself for a potential malfunction. Because false positives could be a precursor to a general sensor failure, it is important that any sensor giving off false positives be immediately checked for a mechanical or software malfunction.

Inconsistent Results

When an H2S detector is giving wildly inconsistent results when compared to other detectors on the site, it is very likely that the detector is starting to malfunction. Networked detectors should be monitored in order to compare every hydrogen sulfide detector to the results of other detectors, and any discrepancies should be immediately investigated. If the discrepancy remains after the detector has been replaced or repaired, the fault may lie with the monitoring network, employee error, or the placement of the detector itself.

Poor Placement

Not all H2S detector failures are mechanical or electronic in nature. In many cases, a detector may fail because of poor placement, such as being put in an area where the airflow works to disperse any H2S concentrations. An H2S sensor should always be placed in areas that conform to the vendor’s instructions regarding hydrogen sulfide sensor placement. In addition, detector issues due to poor placement may indicate a need to install a larger number of detectors in order to ensure adequate coverage of the facility.

Ultimately, having a working network of hydrogen sulfide detectors is a vital part of maintaining a safe workplace. By being proactive in determining the cause of any malfunctions, the company can improve workplace safety while reducing the costs associated with any workplace accidents that occur due to malfunctioning H2S sensors.

-H2S Sensor Types

In industrial settings, there are generally three types of hydrogen sulfide sensors; Metal Oxide Sensing [MOS], Electrochemical, and Optical Sensing Technology. Metal oxide sensors are typically more resilient to humidity and temperature in comparison to other types. The downside is a slow response time and occasional failure until “bump tested” with a higher concentration of H2S with no failure mode. Electrochemical sensors operate using the laws of diffusion and an electrochemical reaction. That sounds great and high tech, but chemical reactions are greatly influenced by temperature, and as such they are a poor choice for austere environments such as a desert or the Artic. Optical sensing technology uses the concept of absorption and measuring the differences in intensity of IR or UV to determine the concentration of H2S. They are a robust solution that is field proven, but they tend to be quite expensive.

-I/O Configuration Options

Typically, a H2S monitor will have a 10-30VDC power similar to most transmitters utilized in control loops. The input points usually allow you to pick between a digital sensor, bridge-style direct sensor and a 4-20 mA analog input. A H2S monitor will also come with a number of programmable relays as an option and the industry standard 4-20 mA output. With the 4-20 mA output, the systems integrator must process that signal with a compute or scaling function at the PLC in order to determine the H2S concentration in PPM. The programmable relays on the H2S monitor provide an alternate way to indicate potentially dangerous hydrogen sulfide levels without relying on a PLC. It is possible to tie these relays to a siren or a strobe light to indicate the area is unsafe and requires operators to wear a self-contained breathing apparatus

-Communications

A good hydrogen sulfide monitor will have a wide variety of communication options. Ethernet is becoming much more common than in years past and is rapidly become the industry standard with the Industrial Internet of Things (IIoT). Typically, the OEM will have a web server on the device that allows configuration. With 10/100 Ethernet capability, it is important to note that the Ethernet/IP, Modbus/TCP and other standards such as EtherCAT can be utilized. Additionally, it is worth mentioning that RS-485 is usually an option on most monitors to support legacy control systems. The advantage of having a multitude of different communication options is ease of calibration.

-Certifications

The final check on H2S Monitors is to ensure that it will be built like a tank for your environment. The main certification you want is CSA Class I, Division 1, Groups B, C, D. You want this because your monitor will be located where there is an explosive gas present.