In the early days of gas detection, instruments were designed to detect a single gas. Most facilities, however, contain a number of gases in any one location vicinity and have a need for dual-channel gas monitors. Today, thanks to advancements in sensor technology and electronics miniaturization, gas detection systems can now measure both toxic and combustible gases at the same time. 

Types of Hazardous Gases

To better understand the power of a dual-channel gas detector, it’s important to note the difference between each hazardous gas, namely toxic and combustible.

• Toxic Gases – Usually emitted from specific chemicals, toxic gases can be found in various environments and are potentially lethal if inhaled. Most toxic gases are colorless and invisible, making them extremely dangerous for facilities that do not have sufficient monitoring systems.
• Combustible Gases – In the presence of oxygen and an ignition source, combustible gases can create sudden flashes of fire or explosions. In addition to causing extreme bodily harm, combustible gases pose a number of risks for equipment and facilities. 

Pro Tip: It’s important to note that certain gases are lighter than air, others are heavier and some remain at “nose level”. This may require that each sensor be located in a different location for maximum efficiency. Properly designed dual-channel detectors support both local and remote sensors for this reason. 

Technology Behind Dual Channel Gas Detectors

Pioneers in gas detection produced sensors that accurately measure the concentration levels of specific target gases in the atmosphere, and this remains true today. However, all toxic and combustible gas sensors have a ‘cross-sensitivity’ to certain gases that are similar in chemical makeup. So a chlorine sensor, for example, will also detect bromine gas, and a catalytic bead sensor calibrated for methane will also detect propane, ethylene and almost any hydrocarbon. 

So in cases where only combustible gases are found, a single detector calibrated for the most combustible gas may be sufficient. But if both methane and hydrogen sulfide might be present, for example, then separate sensors for hydrogen sulfide (a toxic gas) and methane (a combustible gas) should be installed. 

In a properly designed dual-channel gas detector, two sets of independent sensor inputs and analog outputs share a common display and user interface. Channels should operate independently and offer unique alarm levels and calibration capability. 

Installation and Operation of Dual Channel Gas Detectors

Depending on your model, GDS Corp dual-channel gas detectors can support two toxic sensors, two combustible sensors of any combination of both. Both sensors can be installed on the gas detector display unit itself (Called “local sensors”) or in a separate housing that can be mounted some distance away from the display (“Remote sensors”).

In the case of the hydrogen sulfide / combustible gas detector, the hydrogen sulfide sensor would be mounted within 18” of the floor, and the methane sensor within 18” of the ceiling. 

In confined spaces where oxygen levels may be low, a remote sensor should be mounted approximately 5” to 6” above the floor. 

Keep Your Facility Protected

If you regularly work with a large number of hazardous gas, it’s crucial to have comprehensive safety equipment. GDS Corp offers a number of dual-channel gas detectors that can be customized for your specific environment. 

Connect with our sales team to find a gas detection solution to keep your facility safe and protected.

Combustible gas sensors can be designed with two different technologies, catalytic bead sensors or infrared sensors. Catalytic bead sensors detect gas by burning gas molecules on a sensor element. Comparatively, infrared sensors absorb hydrocarbon gas through infrared light at specific frequencies. Learn the advantages of either sensor to find out which technology is best for your work applications.

Catalytic Bead Sensor Advantages

Inexpensive to manufacture and highly reliable, catalytic bead sensors have dominated the market until just recently. Designed with sensor elements that heat up when combustible gas is present, catalytic bead sensors respond to any combustible gas or vapor. With capabilities to detect a broad range of combustible gases, catalytic bead sensors remain a quality choice for gas detection systems.

Pro Tip: Combustible gas detectors measure combustible gas in a range of 0-100% of the Lower Explosive Limit (LEL) value. Be sure to know the LEL limits of the gases you work with to maintain accurate gas detection.

Infrared Sensor Advantages

With increasing popularity in the last two decades, smart infrared (IR) sensors have the advantage of longer calibration and a unique self-test capability. Infrared sensors work by allowing gas to pass between a source of infrared light and a specially designed receiver. When hydrocarbon molecules pass in front of the IR source, they block some of the infrared energy. As a result, the receiver’s output drops and the microprocessor (inside the sensor) generates an output proportional to the amount of absorption.  

Choosing the Right Sensor

Depending on your application, each sensor has its own disadvantages. Infrared sensors can’t detect non-hydrocarbon gases such as hydrogen. In the same way, catalytic bead sensors are sensitive to contaminants and so risk having the atmosphere endanger their sensing elements. Due to the constant danger of explosion, it’s important to have a combustible gas detection system that is reliable, simple to operate, and easy to calibrate.

GDS Corp offers gas monitors that are equipped to support both catalytic bead and infrared sensors:

• GASMAX II
• GASMAX CX

Unlike other detection systems, our design configurations give users the ability to easily switch between the different technologies. Designed specifically for combustible gases, both monitors feature interchangeable catalytic bead and SmartIR infrared sensors. That being said, you can rely on accurate detection, regardless of application, environment, or target gas.

Protect Your Business Facility

Like any hazardous gas in your environment, having an accurate and reliable gas detection system is crucial for protecting your workers. GDS Corp is proud to offer a number of customized solutions for your facility. Whether you’re offshore or in an industrial environment, our detection systems will quickly and reliably alert you of dangerous situations.

Is your gas detection system armed with combustible gas sensors? Connect with our sales team to find a solution that meets your needs.

What Makes a Gas Combustible?

Combustion, in short, is when a substance reacts with oxygen from the air and transfers energy to surroundings as light and heat. Compounds or liquid gases that exceed their flash point (minimum temperature for a liquid gas to ignite in the air) are combustible and can cause an explosion. It’s important to have an accurate detection system to monitor the levels of combustible gases in your air. Learn about the most common types of combustible gases your facility needs to guard against.

All of these substances are in the gaseous state at room temperature. Some are heavier than air, some lighter, and your combustible gas detectors should be mounted accordingly in your facility. 

Acetylene

Flashpoint:  -18.15°C

Commonly used in portable lighting, welding, and cutting, acetylene is a hydrocarbon gas that is lighter than air and fortunately for detection, has a characteristic smell. It is produced by the chemical action of water on calcium carbide and is an appropriate fuel gas for a number of applications.

Butane

Flashpoint: -60°C

The term butane can refer to the alkane n-butane or to its other isomer, isobutane. Commonly found in cooking fuels or blended with propane for commercial use, butane gas is a colorless and odorless gas that is highly flammable.

Ethylene

Flashpoint: 34°C

Deemed as one of the most important manufacturing chemicals, ethylene is a building block for most plastics, antifreeze solutions, and solvents. It also acts as a plant hormone and can aid in the ripening of fruits and flowers.

Pro Tip: Advanced gas detection systems support interchangeable catalytic bead and infrared sensors, enabling users to easily switch between technologies to most rapidly detect the target gas. 

Methane

Flashpoint: -187°C

Methane is the main ingredient found in natural gas. From making fabric, plastic, anti-freeze, fertilizer, and paper materials to powering homes, methane gas is one of the most widely used combustible gases.

Propane

Flashpoint: -156°F

Commonly used for space or water heating, propane gas is a nontoxic and colorless liquid gas. In efforts to decrease air pollution, propane has become a popular substitute for fuels such as gasoline due to its low concentration of pollutants.

Propylene

Flashpoint: -107.78°C

Due to its combustion efficiency, propylene gas is a colorless fuel gas that has a naturally pungent smell. Like propane, it is a nontoxic and clean alternative to gasoline. Its doubled bonded properties give it an advantage over propane, giving it the ability to burn hotter in industrial processes.

Guard Against Combustible Gases

Gas detection is crucial in environments where combustible gases are found, particularly industrial and commercial manufacturing facilities. GDS Corp offers customized gas detection systems for your business, regardless of your size. With accurate detection and user-friendliness, you can rely on our products to keep you safe long term. 

Do you regularly work with combustible gases? Connect with our experts to find the best solution for your environment.