What Gases Can Set Off a Gas Leak Detector?

Most of the homes and commercial properties in the UK use gas for different purposes, such as heating and cooking. Gas is considered as an economical and efficient energy source. It is also referred to as a safe and environment-friendly source of energy.

But it does have some risks associated with its use. Natural gas burns when exposed to a flame. So, the largest threat in using gas is its ability to cause a fire, especially when it starts leaking. In such an eventuality, it may also cause an explosion. Another potential risk associated with natural gas is the emission of carbon monoxide. If any gas appliance develops a fault, resulting in incomplete combustion of gas, it starts generating carbon monoxide.

Burning natural gas may also result in a deficiency of oxygen and an increased level of carbon dioxide if it is burnt in a confined environment. Additionally, there are some other harmful gases that can affect the occupants, such as hydrogen sulfide or methane. Collectively all such gases can be classified under the category of combustible gases. Hence, making your premises safe from any risks associated with these combustible gases is important. The gadget that can help you in this endeavor is a gas leak detector.

Dangerous Gases for Living Beings

Air comprises a mixture of different gases, with oxygen being the one that is essential for life. If the ratio of these gases is disturbed due to any natural or unnatural factors, it may become dangerous for human and animal life. Even the vegetation may also be affected by any such imbalance.

Homes, commercial, and industrial premises may face this problem so often. It happens due to the emission of some harmful gases due to domestic and industrial activities. Natural gas, carbon monoxide, hydrogen sulfide and methane are amongst the potentially dangerous gases that may accumulate in your premises unwarrantedly.  

Let’s try to understand some of these harmful gases and their associated risks:

• Natural Gas

Although natural gas is quite safe, when it remains confined in the pipework and appliances, it may cause serious threats to people and properties when it gets out. The most serious threat is an eruption of fire and explosion, which may happen due to un-attended leakage of natural gas from any of the eroded pipework or a faulty gas appliance.

Additionally, prolonged exposure to natural gas can pose serious health and medical issues for humans and animals.

• Carbon Dioxide

While natural gas is itself harmful in the shape of causing a fire, its normal burning results in the generation of Carbon Dioxide. Another impact of burning natural gas is the consumption of oxygen, which is also a natural burning process.

If natural gas is burnt in a confined place, it may result in a decrease in oxygen levels and an increase in carbon dioxide in the atmosphere. Any such situation will be a serious health issue for humans. However, if there’s ample fresh air near the point of burning natural gas, the oxygen and carbon dioxide gas ratio is naturally maintained without causing any immediate danger.

• Carbon Monoxide

On the other hand, carbon monoxide is a real danger when it comes to the harmful gases in a building, whether domestic, commercial or industrial. It is more commonly referred to as CO. Carbon monoxide is quite a dangerous gas, being colorless and odorless. It is sometimes also referred to as a silent killer.

Like Carbon Dioxide, it is also associated with burning natural gas. It is generated due to incomplete or defective burning of natural gas, which may happen at any time due to a faulty gas burner in your kitchen. It can also be generated from water heaters, flues and any other gas or oil-operated appliances. Flameless chemical heaters, if used indoors, can also cause the generation of carbon monoxide. A blocked or choked flue is also a source of CO generation.

Carbon monoxide results in serious medical situations, mostly by way of carbon monoxide poisoning. The most common symptoms of CO poisoning may be headache, nausea, weakness, stomach disorder, dizziness, chest pain and vomiting. It also causes shortness of breath, confusion, low blood pressure, impaired judgment and increased heartbeat. Prolonged exposure to CO may also result in death. This gas is equally harmful to pets.

• Other Toxic Gases

Normally you come across natural gas and carbon monoxide hazards in residential properties. However, some other hazardous gases are mainly found in industrial and commercial units. These may include methane and hydrogen sulfide.

Methane is relatively less toxic but is quite dangerous due to its ability to cause a fire. Additionally, it replaces oxygen very quickly. It is normally produced in oil refineries and other petrochemical units. Hydrogen sulfide is highly toxic as well as flammable. Exposure to higher levels of this toxic gas results in quick death.

Some refrigerants, which are used in cold storage, often leak and may cause serious health issues in humans. It can also affect the environment. Redon is yet another harmful gas that may accumulate, mainly in basements, and is one of the major causes of lung cancer.

Gas leak detectors are the main gadgets normally used in homes and industrial units to detect these hazardous gases.

Understanding Gas Leak Detectors

Most of the properties, whether residential or commercial and industrial, are equipped with an integrated safety system. Gas leak detectors are an essential part of this system. Sometimes a gas leak detector is also used in isolation, mostly in small domestic properties.

Gas leak detector is a device that is meant for detect the presence of different harmful gases in a particular place. It is equipped with sensors that are capable of sensing such gases. These are mainly programmed to sense one or a set of harmful gases such as carbon monoxide, methane or hydrogen sulfide. However, gas detectors, mostly used in homes, are mainly designed to detect the presence or leakage of natural gas and carbon monoxide. However, the carbon monoxide detectors are mostly used separately, as they are specifically made for this purpose and may not detect any other gases.

Appropriate Installation of a Gas Leak Detector

Gas leak detectors can perform more effectively if installed appropriately at the right location. Here are some useful tips on installation.

• Gas leak detector should be installed in such a way that it gets an uninterrupted power supply, 24/7.
• It should be connected to the safety hub of the building so that you can receive emergency alerts. It may, however, be used as a stand-alone device in small premises.
• The best place to install a gas leak detector might be the areas that are more susceptible to a possible gas leak.
• Natural gas normally accumulates near the ceiling, as it is lighter than air. Hence in case of leakage, it starts traveling upwards and gets stuck near the ceiling. So, the best place for the installation of a gas leak detector would ideally be the ceiling. It is advisable to install it 6-8 inches below the ceiling.
• If you are looking to detect carbon monoxide, the best place would be near the areas where the burner of cooking hubs is working or near the flues. Carbon monoxide is generated as a result of incomplete combustion of natural gas; hence, it is more likely to concentrate somewhere near these points.
• If the property is relatively larger, you may have to install more than one gas leak detector at different locations. This will help secure the entire building.

Main Categories of Gas Leak Detectors

There are two types of gas leak detectors used in homes and industries:

• Portable gas leak detector – The safety personnel in commercial and industrial units normally uses this type of gas detector. As the name suggests, it can be carried along while the safety official walks through the premises to see whether or not there’s an accumulation of any harmful gases. This can be handheld or hooked with the harness or belt of the safety personnel. It can sense the harmful gases and generate alerts in the shape of blinking lights or beep sounds.  
• Fixed gas leak detectors – Mostly used in homes and industries to detect harmful gases. These are normally wall-mounted or fixed in the ceiling. These can be used in isolation or as a part of an integrated safety system. It can pass on the alert to the main safety hub, which triggers the alarm to alert the monitoring staff to take remedial action.

Further Grouping of Gas Leak Detectors

• Electromechanical

In this type of gas leak detector, gases present nearby are diffused through the porous surface of the detectors onto an electrode. Here the gases are chemically oxidized, producing current. The quantity of current generated indicates the amount of gas accumulated on the electrode.

This type of gas detector is considered more reliable and durable, as it needs less maintenance. However, the sensors have to be replaced after a certain period, ranging from one to two years. These are mostly used in chemical plants, refineries, and gas turbines.

• Photoionization

High photon energy Ultra Violet lamps are used in this type of gas detector for ionization of the chemicals present in the gas that comes in contact with the sensors. This type of gas detector is mainly used in industries.

• Catalytic Beed

This type of gas leak detector is useful for the detection of ignitable gases. A combustible gas can cause explosion if its level ranges between LEL (lower explosion limit) and UEL (upper explosion limit). The catalytic beed gas leak detector measures the presence of combustible gases that come in contact with its sensors and sounds an alarm or blinks a light indicating the potential threat of accumulation of such gases.

• Semi-Conductor

Also known as metal oxide semiconductor. They detect the hazardous gases through a chemical reaction on the gases that touch the sensors. This type of detector is quite useful in detection of carbon monoxide, hydrogen sulpher, ammonia and sulpher oxide. However, it can start malfunctioning in high humidity levels.

• Ultrasonic

This type of gas detector senses the leakage with the sound produced when pressurized gas gushes out of a small opening and produces a typical sound. Ultrasonic detectors cannot recognize the type of gas; they only detect something producing sound, which often is a gas leak.

• Other Types

Apart from the above, there are a few other useful gas sensors, such as Holographic, Infrared point, and infrared imaging sensors.

Gases That Can Set Off the Gas Leak Detector

A gas leak detector is essentially designed to detect the presence of dangerous and harmful gases in the atmosphere. This is made possible through various electrochemical processes in most of the detectors. However, others may sense a leakage through the unique sound of a leaking gas. But in this case, the detector is not able to identify the type of gas.

So, the gas leak detector can set off when it detects or senses any of the gases, for which it is programmed. Generally, a gas leak detector gets triggered when one or more of the following gases accumulate in the premises beyond the permissible ratio.

1. Natural gas – Especially in case of accumulation beyond the tolerable level
2. Carbon monoxide
3. Increased level of carbon dioxide
4. Deficient level of oxygen
5. Excessive level  of oxygen – relevant to certain industrial units
6. Methane – it can penetrate into homes and tends to accumulate in confined pockets and is highly inflammable
7. Hydrogen Sulfide
8. Any other gas from the combustible group of gases

Conclusion

Detection of harmful gases is highly important for domestic as well as non-domestic properties. Most of the safety systems of such properties essentially have one or more gas leak detectors as part of the comprehensive safety plans. The role of gas leak detectors is to sense and identify one or more hazardous gases and generate an alert when it crosses a certain level.

However, in most cases, you may need to install separate gas leak detectors for some of the dangerous gases, such as carbon monoxide. These detectors may either be a part of the main safety system or may function as stand-alone. In any case, the role of all such gas leak detectors is to generate alerts. So, they get triggered when any of the gases for which they are designed crosses a certain level of presence in the air. But the key to the success of these detectors is their appropriate installation at the right locations.