Gas & Flame

Neal Systems provides gas and flame solutions optimized for your specific requirements including:

  • Safety
  • Process Control
  • Regulatory Compliance
  • Gas Leak Detection
  • Flame Detection
  • Process Gas Analyzers

View our Product Line Card

See our Top FAQs for Gas & Flame Detection

Technology Types



Flame Ionization

Gas Chromotography

Gas Filter Correlation


Laser Moisture



Thermal Conductivity



Tunable Diode Laser

Draeger Product Solutions

The largest manufacturer of gas detection equipment in the world, Draeger offers a wide range of products designed for toxic and explosive gas detection in a variety of environments.


The new 8000 series transmitters incorporate HART communications with a user friendly display for easy calibration.

fixed gas detection


Draeger offers a wide range of sensors to detect a variety of gases suitable for a variety of applications.


Draeger portables use the industry’s most stable and longest lasting sensors for a low maintenance and economical solution to personal gas detection.

portable gas detection


Draeger offers a full range of products – from testing devices to software to calibration gases – to meet your gas detection testing and calibration needs.

bump testing


Draeger’s flame detection cameras are available for visible, infrared, and ultraviolet flames. The Flame 5000’s advanced detection algorithms practically eliminate false alarms.

flame detection smart camera


The Draeger X-Zone 5000 turns the X-am 5000 into a portable area monitor. Multiple X-Zones can be wirelessly interconnected to form a fence line of gas detection.

draeger x-zone 5000


Measure gas concentrations or collect samples for further analysis with Draeger tubes.

draeger tubes

Process Gas Analyzers


Servomex manufactures gas analyzers (including the Delta F line of gas analyzers) for a broad range of gas measuring applications including the industries of industrial gases, hydrocarbon processing, metals & mining, power generation, and regulatory requirements. Their global service and engineering team have long been at the forefront of technology innovation in industrial gas analysis. For close to 60 years, Servomex has been the leader in paramagnetic oxygen technology measurements, but are quickly becoming the choice for the newer Tuneable Diode Laser (TDL) technology. The new Mini-Laser is the world’s smallest cross-stack TDL for oxygen measurements.

Gas Types Measured by Servomex Analyzers

Ammonia (NH3) Argon (Ar) Carbon Dioxide (CO2) Carbon Monoxide (CO)
Combustibles Helium (He) Hydrocarbon Mixtures (C1 – C5) Hydrogen (H2)
Hydrogen Chloride (HCl) Hydrogen Cyanide (HCN) Hydrogen Fluoride (HF) Hydrogen Sulfide (H2S)
Methane (CH4) Nitric Oxide (NO) Non-Methane Hydrocarbons (NMHC) Oxygen (O2)
Propane (C3H6) Sulfur Dioxide (SO2) Total Hydrocarbons (THC) Water Moisture (H2O)


MTL’s product line of Hitech gas analyzers are used across a variety of applications in all environments, including hazardous areas, and across all industrial and process sectors. With a carefully thought-out range of products – each with a set of complementary options – Hitech analyzers can be found for most applications. The installed base of Hitech products includes equipment used in digester gas analysis, landfill gas monitoring, CDM verification, gas-to-grid, CHP engine protection and efficiency, and flare stack monitoring.

gas analyzerskatharometersoxygen detectors

Regal Gas Chlorinators

Used world-wide for municipal water treatment and wastewater treatment, REGAL products have a wide range of industrial, commercial, and agricultural applications, and allow the use of chlorine gas, which is the most economical method of disinfection, without sacrificing safety or reliability. Because of their quality products and famous support, REGAL is the foremost manufacturer of water treatment equipment in the world.

Regal Gas Chlorinators

Top FAQs

Q: What is unique about Draeger’s toxic gas detection sensors?

Draeger uses patented, proprietary technology for long life and resistance to false alarms. Draeger electrochemical sensors offer faster response, higher accuracy, and greater stability. The robust, long-life sensors for Draeger transmitters are used for the selective measuring of the smallest concentrations of toxic gases and oxygen in ambient air under ambient conditions. The DraegerSensor XXS is a giant step into the future by being remarkably compact and providing even higher performance than the competition. DraegerSensors XS are ahead of the field thanks to their high reliability and warranty periods of up to 5 years. Draeger’s smart technology allows simple sensor installation and switching using plug-and-play.

Q: What is different about Draeger products that make them the best solutions for gas and flame detection?

Draeger provides overall Life Safety Solutions, which offer a variety of solutions including gas leak detection (asphyxiant, toxic, explosive) and flame detection (UV, IR, UV/IR, Triple IR, and flame camera). These solutions include these unique technologies:

  • Flame Camera – Traditional UV, IR, UV/IR, or Triple IR technologies for on-site flame detection will sometimes produce false alarms that can be unexplainable. Whatever the cause of the alarm, someone still must go to the area to investigate. Draeger’s flame camera solution solves both these challenges using a closed-circuit television (CCTV) chip in an explosion-proof housing. This smart chip has 10+ years of algorithms from all types of flames that applies these three criteria: 1) three dimensional (e.g., it won’t respond to a reflection of a flare on a metal tank), 2) moving (e.g., a torch wouldn’t cause a response), and 3) visible (e.g., hydrogen flames can’t be detected by it). If a flame is sensed, the on-board video buffer holds 7 seconds before the flame and 7 seconds afterward so that you can review what caused the flame and what happened immediately afterward. For more information, see the manual at the following web link:
  • Infrared Technology for Explosive Gas Detection – Draeger builds on well-established infrared technology with its new innovations. The Draeger 8700IR features a dual-beam sensor (MTBF of 25 years) with a patented fluted mirror design that significantly minimizes the effect of dust/dirt in the sensor, thereby requiring less cleaning. In addition, Draeger scientists have tested and programmed the actual 0 to 100% LEL curves of 34 different explosive gases so that the calibration is accurate across the whole 0 to 100% range, not just at the zero and span point. The Draeger 8700IR lasts longer, needs calibration only every 1 to 2 years, and requires less cleaning maintenance. Many of Neal Systems’ oil and gas customers have come to use Draeger because of this unique infrared technology.

In addition to the above unique technologies, Draeger offers the following distinctive capabilities and features to meet the gas and flame detection needs at your facility:

  • Electrochemical Cell Technology – Draeger electrochemical sensors for oxygen and toxins are known for these features that sets them apart:
    • Long Life Typically lasting significantly longer due to a large electrolyte reservoir and non-consumptive chemical reactions (not all sensors are non-consumptive). Sensors typically last 2 to 3 times longer than their typical equivalents from other manufacturers.
    • Minimal Drift and No DOA between Calibrations In most cases, we recommend that our sensors be calibrated every 6 months instead of every 1 to 3 months for traditional sensors. Draeger sensors have a unique design and on-board diagnostics to ensure that a sensor won’t die without warning. The drift between calibrations should also be minimal compared to most other electrochemical sensor technologies.
    • Minimal Pressure/Humidity/Temperature Fluctuation The sensor design includes a patented system to minimize fluctuations.
  • Catalytic Bead technology – Draeger’s scientists recently released a patented new Cat Bead sensor that has about 2 to 3 times faster response than the traditional Cat Bead. It has almost no zero drift, possesses significantly longer life when exposed to poisons such as H2S, and has almost no drift related to sensor orientation.
  • Transmitter technology – Draeger’s new series features two unique items, SIL 2 rating and advanced sensor diagnostics. The latter supports predictive maintenance by telling you how much sensor life you have left, how much the zero and span are off, and the sensor’s response over the last 15 minutes.
  • Sampling Panels – Draeger has invested heavily in their sampling panel team, allowing the design and deployment of systems and sampling panels that enable gas monitoring in situations where water, particulates, temperature, pressure, or other problems would prevent accurate or consistent measurement of target gases.
Q: How do advances in Draeger “DD” sensor technology solve common problems in gas and flame detection?

Draeger “DD” sensor technology addresses a variety of gas and flame detection problems as follows:

  • Enhanced Accuracy

    Problem: Accuracy levels on traditional catalytic bead sensors are not as good as most folks would like, especially around zero (i.e., a lot of “zero drift”).

    Draeger Solution: Draeger “DD” sensor technology enhances accuracy with less drift. Two active pellistors (beads) rather than one active / one non-active allow for a significant reduction in the resistance readout differences between the two pellistors.

  • Perfect Mounting Requirement Eliminated

    Problem: Traditional catalytic bead sensors have to be mounted perfectly in the horizontal and preferably in a location with minimal temperature change in order to avoid heat changes/fluctuations between the pellistors that cause erroneous drifting/readings.

    Draeger Solution – The need for “perfect mounting” (horizontal, minimal temperature shifts) is eliminated. The new design surrounds one of the active pellistors with an enclosure that minimizes the heat transfer between the two pellistors.

  • Quicker Speed of Response

    Problem: Instrument response time is too slow.

    Draeger Solution: Draeger technology enables a quicker response through its lattice-type wire-mesh covering sensor. This technology is superior to the traditional sintered stainless steel XP covering where big hydrocarbons take a longer time to work their way through the sintered steel cover. The Draeger solution allows molecules to move comparatively quickly through the wire mesh. Except for hydrogen, the newer type observed a reduction of 2 to 3 times in response time for hydrocarbon molecules.

  • Degrading of Pellistors

    Problem: Catalyst on the pellistors can get poisoned by certain gases, especially H2S, wet HCl, and vinyl chloride.

    Draeger Solution: Draeger technology reduces the poisoning effect of H2S, wet HCl, and vinyl chloride. The Draeger DD sensor uses a different catalyst than the traditional solution and has a slightly different design that minimizes the effect of these gases.

Q: What is unique about Draeger’s infrared LEL gas detection sensor?

The DraegerSensor IR can replace catalytic ex-sensors (catalytic bead sensors, pellistors) without additional installation work, enabling an easy, rapid upgrade in sensor technology.

Q: What is unique about Draeger’s flame camera?

Draeger flame cameras offer reliable detection of flames and high immunity against false alarms. Due to their different connection possibilities, Draeger detectors can be used in a very wide range of applications. The Draeger models are based on IR, UV, IR/UV combined, and visible light technologies and are built to operate in explosion-hazard areas. The Draeger Flame 5000 analyzes live color video signals through digital signal processing and software algorithms and can also perform double duty as a surveillance camera.

Q: How do I design an effective gas detection/monitoring solution for an area of my facility?

Gas detection design relies on both technology and technique. In general, look at your facility’s process design drawings and consider where gas leaks can happen. Look seriously at the safety standards you are required to meet. To ensure a high level of safety, make sure you are using the proper technology to address the hazard by knowing the latest sensing technologies, which technology is best for the application, and where detectors should be installed for maximum protection.

Three main types of fixed gas detectors are generally available:

  • Point-type – These gas detectors can be fitted with either combustible or toxic gas sensors. These detectors monitor a specific area or point within the facility and must be strategically located for early detection of gas. These detectors require calibration for the gas type to be detected. Point-type detectors also must be routinely inspected to ensure they are capable of performing as expected.
  • Open-path or line-of-sight – These gas detectors monitor the presence of combustible hydrocarbon gases within a beam of infrared light projected between a pair of modules. To ensure that the gas/vapor hazard passes through the light beam, the modules must be strategically located and properly aligned. As with point-type detectors, open-path detectors must be calibrated for the gas type to be detected. Typically, open-path detectors are self-monitoring in the case of a blocked light beam or similar trouble.
  • Analytic/sampling gas detection – Many point-detection and analytical instruments use a sampling system technique to extract an air sample, direct the sample to a sealed sensor where it is analyzed, and then exhaust or return the sample to a safe location. Sampling system components typically include a vacuum pump, sensor(s), flow meters, filters, and flow control elements. They are generally mounted on a subplate installed within an enclosure with compression fittings for sample tubing connections.

Fixed gas detection systems provide alarm output signals to alert people and initiate corrective action. The alarm settings must be low enough to ensure the safety of people and equipment, but should not be so low as to cause false alarms, sometimes caused by background gases, sensitivity to other gases or vapors, or sensor signal drift. If false alarms are a problem, one option is to use voting in which two detectors must detect hazardous gas levels before the alarm activates. In determining optimum alarm levels for fixed gas detection systems, consider the following:

  • Applicable industry standards or codes
  • Fire/explosion risk of the gas(es)
  • Toxicity of the gas or vapor
  • Typical background gas levels
  • Size and magnitude of the potential leak
  • Whether the area is occupied or unoccupied
  • Time required to respond to the alarm
  • Corrective actions required

Although gas detection system design and performance requirements exist under some regulatory authorities, there are no documented rules concerning optimal detector placement or quantity requirements. Hazardous operation (HAZOP) analysis, along with proper planning and placement of sensors, is the first step in protecting workers and assets from gas hazards within a facility. Best practices show that the most effective way to determine optimal sensor installation points is to identify the most-likely sequence of events leading to a gas leak and the probable environmental conditions during the leakage. The following considerations should be taken into account when evaluating optimal placement and quantity of gas detectors:

  • Gas or vapor source – To locate potential gas or vapor sources, review Process and Instrumentation Diagrams (PIDs), facility maps, and hazardous-area classification drawings. Evaluate the characteristics of potential sources including pressure, amount at the source, source temperature, and distance. Common areas for releases include pump and compressor seals, instrumentation sources, valve seals, gaskets, and sample points.
  • Ignition source – After determining the presence of combustible gas, identify sources of ignition (e.g., sparks or high-pressure gas release areas). Place the detector between the ignition source and any potential source of the gas or vapor.
  • Gas density or buoyancy – Gas or vapor that is less dense than air (1.29 g/cc at normal conditions) will rise in still air. Gas or vapor that is denser than air will settle to lower elevations in still air. The detector typically should be placed 45.7 to 61 cm (18 to 24 inches) above the level where the gas would settle. Remember that temperature affects the density of a gas. Heating decreases the density of a gas and makes it lighter. In fact, heating or cooling a gas by 30°C (54°F) changes the gas density by approximately 11%. Pre-stratification by thermal sources can delay or prevent gas detection near heated areas or ceilings. This typically occurs where heat sources are near the ceiling or where roof decks are heated by solar radiation and no suitable mechanical ventilation is provided. If such pre-stratification potentials are present, then placement of the detector in area(s) unaffected by the stratification is recommended.
  • Indoors/outdoors – The environmental setting greatly influences vapor dispersion characteristics and gas detection ability. Typically, indoor settings mean that the overall hazardous area is well contained and that air flow can be identified and controlled. Ceilings and walls usually are the likely areas for gas accumulation and area delineation. Point(s) of human contact are usually identifiable. Outdoor settings mean the air flow is less controllable with few distinct areas of gas accumulation. These areas present a challenge that requires comprehensive application analysis and sound engineering judgment.
  • Ambient temperature – Determine the maximum ambient temperature. Include all nearby hot surfaces such as motors, pumps, or steam lines. The maximum ambient temperature plus a safety factor of 50°C to 60°C should be less than the flash point of the monitored gas.
  • Location of personnel – Particularly in situations dealing with toxic gases, it is extremely important to consider the locations of people at the facility. To place a sensor accurately between the leak source and the people, review PIDs, facility maps, and hazardous-area classification drawings.

Optimal protection of a facility can be achieved through the simultaneous use of both open path and fixed gas detectors. Point detectors should be installed at or near known high-risk gas leakage points or accumulation areas to provide specific information on the level of gas present at these areas. Open-path gas detection systems should be installed at plant or process area boundaries where they can monitor the plant perimeter and indicate overall gas cloud movement in and out of the facility. It is possible to identify and track the movement of gas clouds throughout the facility by monitoring the output signals of all the gas detectors on a common workstation graphic display screen.

Q: When should I replace my sensors?

There is really no recommended maintenance schedule for replacing the sensors in a portable gas monitor. You should not look at the sensors like changing the oil in your car, but more like filling the gas tank. When the sensors do not have enough sensitivity to calibrate successfully, they are essentially out of gas and should be replaced. As long as there is still “gas in the tank,” the sensors are okay for use.

One method is to determine the sensor’s span reserve value. This is the measure of sensitivity in the sensor, which is determined during calibration. It is displayed on the monitor for each sensor at the end of calibration and is stored in the instrument calibration records. Sensors with a span reserve value less than or equal to 50% of the calibration gas concentration are out of gas, will fail calibration, and must be replaced. The “low fuel light” will come on when the span reserve value is between 50% and 70% of the calibration gas concentration, indicating that the sensitivity is marginal and that you may want to consider refueling your monitor by replacing the sensors before the tank is completely empty.

In short, as long as your sensors have enough sensitivity or span reserve to calibrate successfully, they are serviceable. There is no need to change the sensors until they fail calibration and can no longer be used. Keep your eye on the gas gauge – the span reserve value – and you won’t be caught without gas in your sensor’s tank.

Q: How often do I need to calibrate my sensors?

This is a very common question about gas detectors. Most common sensors are designed so that, with normal use, they will only lose 5% to 10% of their sensitivity per year. However, there are a number of reasons why a sensor may unexpectedly lose additional sensitivity or even fail to respond to gas. Such reasons include desiccation, poisoning, physical restriction of airflow, overexposure, internal leakage, or mechanical damage due to physical shock and immersion.

With so many reasons why a sensor can lose sensitivity, and given that dependable sensors are critical to survival in a hazardous environment, frequent verification of sensor performance is paramount. There is only one sure way to verify that a sensor can respond to the gas for which it is designed: expose it to a known concentration of target gas and compare the reading with the concentration of the gas to ensure that it is within a manufacturer’s recommended tolerance limits. This is called a “calibration check.” This test is very simple and takes only a few seconds to accomplish. The safest course of action is to do a “calibration check” prior to each day’s use. It is not necessary to perform a full calibration (adjustment) unless readings for LEL and toxic gases/vapors are outside of the range of 90% to 120% of the expected value. For oxygen, the acceptable range is considered to be ±0.5% vol., so 20.4% to 21.4% O2 in ambient clean air or via application of zero air. Further for oxygen, for the application of Sperian 18.0% O2 balance gases, the reading should again be within ±0.5% vol., so 17.5% to 18.5% O2.

A number of leading gas detection equipment manufacturers have participated in the development of guidelines concerning the recommended frequency and types of detector performance tests. If your operating procedures do not permit ongoing daily calibration checks, consider the following procedure:

  1. During a period of initial use of at least ten days in the intended environment, perform a calibration check daily to be sure there is nothing in the atmosphere that is poisoning the sensor(s). The period of initial use must be of sufficient duration to ensure that the sensors are exposed to all conditions that might have an adverse effect on them.
  2. If these tests demonstrate that it is not necessary to make a full calibration (adjustment), the time between checks may be lengthened. The interval between calibration checks should not exceed thirty days.
  3. When the interval has been extensive, the toxic and combustible gas sensors should be replaced upon warranty expiration. This will minimize the risk of failure during the interval between calibration checks.
  4. The history of the instrument response between checks should be kept. Any conditions, incidents, experiences, or exposure to contaminants that might have an adverse effect on the calibration state of the sensors should trigger an immediate calibration check before further use.
  5. Any changes in the environment in which the instrument is being used, or changes in the work which is being performed, should trigger a resumption of daily calibration checks.
  6. If there is any doubt at any time as to the accuracy of the sensors, perform a calibration check before further use. Gas detectors used for the detection of oxygen deficiencies, flammable gases and vapors, or toxic contaminants must be maintained and operated properly to do the job they were designed to do. Always follow the guidelines provided by the manufacturer for any gas detection equipment. If there is any doubt regarding your gas detector’s accuracy, perform a calibration check.
Q: Where are good sources of information about the dangers of various gases?

For various resources about dangers associated with gases, see Draeger’s website.

You can also access Material Safety Data Sheets (MSDSs) for hazardous gases at this website.