In manufacturing facilities or environments where hazardous materials are present, there are often a number of gases that need to be monitored. Understanding dual-channel gas detectors are essential to ensure that you have the most cost-effective gas detection system for your industry.
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.