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How Do Dual-Channel Gas Detectors Actually Work?

Posted by on Apr 10, 2020 in Combustible Gases, Dual Channel Detectors, Toxic Gas | 0 comments

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.

Thanks to innovative technology, gas detectors can be configured to detect more than one gas at the same time. Learn how they work in detail here.

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.

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5 Types of Toxic Gas & Their Health Effects

Posted by on Apr 3, 2020 in Gas Emission, Toxic Gas | 0 comments

Every manufacturing industry, from oil and gas to chemical production, deals with various types of toxic gas. Maintaining healthy levels of these dangerous gases is essential to protect the wellbeing of employees and warehouse workers. Depending on the concentration and environment, toxic gases can be corrosive, flammable, and highly lethal. For your safety, make sure you adequately understand the severity of the toxic gases in your vicinity.

How many of these toxic gases do you deal with on a regular basis? Learn the facts behind the most common types of harmful gases here.

5 Types of Toxic Gas & Their Effects, GDS Corp, Houston, TX

Common Types of Harmful Gases

Gas detection experts have defined a toxic gas as “one which is capable of causing damage to living tissues, impairment of the central nervous system, severe illness or, in extreme cases, death when it is ingested, inhaled, or absorbed by the skin or eyes.” Technically, gases are generally considered toxic if the median lethal concentration is greater than 200 parts per million (ppm). 

Depending on your industry, you may come into contact with numerous harmful gases on a daily basis. Examine the health effects of the following five common toxic gases:

  1. Hydrogen Sulfide
  2. Carbon Monoxide
  3. Nitrogen Oxides
  4. Ozone
  5. Solvents

1) Hydrogen Sulfide

Primarily identified by its “rotten egg” smell, hydrogen sulfide (H2S) is found in a number of manufacturing processes and chemical substances. Products such as pesticides, plastics, pharmaceuticals, landfills, and even breweries emit hydrogen sulfide as a byproduct. The toxicity levels of hydrogen sulfide emissions are dangerously high, especially if not disposed of properly. Inhalation of high concentrations of H2S can result in irritation, unconsciousness, memory loss, or in severe cases, instant death.

Severity Level: OSHA currently recommends a 10-minute ceiling level of 10 ppm for workers. In addition, 100 ppm of H2S exposure has been proven to have immediate lethal consequences, making it highly toxic, even at these low concentration levels.

Pro Tip: Install an H2S gas detector to monitor specific levels of H2S concentration in your vicinity, no matter what other gases may be present.

2) Carbon Monoxide

Generally found in industrial processes as a source of energy and reducing agent, carbon monoxide (CO) is a tasteless, odorless, and colorless gas. When materials are burned improperly, the emissions of carbon monoxide are highly poisonous, especially in crowded areas where human exposures can’t be monitored. Health effects such as nausea, restlessness, and euphoria may be experienced with repeated exposure causing eventual death. 

Severity Level: OSHA currently recommends 50 ppm for workers during an 8-hour time period, and maritime workers may need extra attention if the CO concentration is greater than 100 ppm. Concentration levels beyond 200 ppm are considered highly dangerous.

3) Nitrogen Oxides

Nitrogen oxides encompass seven different gases, with nitric oxide and nitrogen dioxide being the two most common forms. Found in a number of consumer and industrial environments, nitrogen oxides are the main contributor of air pollution and reduced air quality. Nitric oxide is often emitted from vehicles, agricultural processes or as a byproduct of combustible fossil fuels, and nitrogen dioxide has been used in the production of rocket fuels and explosives. According to the CDC, health effects vary from eye, skin, and respiratory tract irritation to acutely lethal circumstances.

Severity Level: Health officials are constantly trying to find ways to limit exposure to nitrogen oxides. The current permissible limit for nitric oxide is 25 ppm within an 8-hour work shift, with 100 ppm being immediately lethal. Comparatively, nitrogen dioxide has a 5 ppm permissible limit and 20 ppm lethal concentration limit.

4) Ozone

Especially toxic to plant life and humans, ozone is a gas made up of three oxygen atoms (O3) and is usually seen as widespread smog across cityscapes. While it may occur naturally in the upper atmosphere of the stratosphere, chemical reactions resulting from vehicle exhausts or gasoline vapors contribute to large ozone concentrations at ground level. Health problems such as decreased lung function, respiratory infection, UV overexposure (i.e. sunburns) or skin cancer in humans make it a toxic substance that must be monitored continually.

Severity Level: According to OSHA, ozone levels should never exceed the following average: 0.10 ppm (parts per million) for 8 hours per day exposure. While the level of work may contribute to the actual level, extreme caution must be administered when working near ozone for an extended period of time.

5) Solvents

In addition to being highly flammable, the properties of organic solvents are highly toxic. Organic solvents are carbon-based substances capable of dissolving or dispersing one or more other substances. Solvents usually found in kerosene, gasoline, paint strippers, and degreasers are highly flammable and at high concentrations, can affect your central nervous system. Other side effects such as dizziness, drowsiness, lack of concentration, confusion, headaches, coma, and death can be experienced during long term exposure of solvents.

Severity Level: Due to the various forms of solvents used on a daily basis, OSHA has published individual guidelines for every toxic chemical gas that has been identified. Review the standards of the toxic gases you may encounter to protect your long term health.

Protecting Your Health

When the health of your employees is at risk, measures must be put in place to ensure safe working conditions. GDS Corp offers a wide range of electrochemical sensors and photoionization detectors (PID) that can detect the presence of toxic gases at very low levels. Equip your facility with protection you can rely on with detection customized and tested for your hazardous environment.

Connect with our gas safety experts to find the best detection system for your facility.

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