Blogs listed by tag: portables

What is IR Technology? 

Infrared emitters within the sensor each generate beams of IR light. Each beam is measured by a photo-receiver. The “measuring” beam, with a frequency of around 3.3μm, is absorbed by hydrocarbon gas molecules, so the beam intensity is reduced if there is an appropriate concentration of a gas with C-H bonds present. The “reference” beam (around 3.0μm) is not absorbed by gas, so arrives at the receiver at full strength. The %LEL of gas present is determined by the ratio of the beams measured by the photo-receiver. 

Benefits of IR technology 

IR sensors are reliable in some environments that can cause pellistor-based sensors to function incorrectly or in some cases fail. In some industrial environments, pellistors are at risk of being poisoned or inhibited. This would leave a worker on their shift unprotected. IR sensors are not susceptible to the catalyst poisons so significantly enhance safety in these conditions. 

Pellistor technology is considerably less expensive than IR technology, reflecting the comparative simplicity of the detection technology. However, there are several advantages of IR over pellistors. These include IR technology provides fail-safe testing. The mode of operation means that if the infrared beam failed, this would register as a fault.  In normal pellistor operation, conversely, a lack of output is ordinarily an indication that no flammable gas is present, but this could also be the result of a fault. Pellistors are susceptible to poisoning or inhibition; a particular concern in environments where compounds containing silicon, lead, sulphur and phosphates, even at low levels. IR instruments don’t, themselves, interact with the gas.  Only the IR beam interacts with the gas molecules, so, IR technology is immune to poisoning or inhibition by chemical toxins. In high concentrations of flammable gas, pellistor sensors can burn out. As with poisoning or inhibition, this would probably only be picked up by testing.  Again, IR sensors are not affected by these conditions. Low levels of oxygen mean that pellistor sensors won’t work. This can be the case in recently purged tanks, but also in confined spaces generally, where pellistors may be ineffective.  IR technology is effective in areas where oxygen may be reduced or absent. 

Factors that affect IR technology  

Exposure to high levels of flammable gas can cause “sooting” of pellistors, reducing their sensitivity and potentially leading to failure. Pellistors require oxygen to function, however, IR sensors can be relied on in applications such as fuel storage tanks where there is little or no oxygen, due to flushing with inert gas prior to maintenance, or which still contain high levels of fuel vapours. The fail-safe nature of IR sensors, which automatically alert you to any fault, provides an additional layer of safety. Gas-Pro IR measures in %LEL and has been certified for use in hazardous areas as defined by both ATEX/IECEx and UL. 

Knowing when the technology has failed  

IR sensors are reliable in environments that can cause pellistor-based sensors to function incorrectly or in some cases fail. In some industrial environments, pellistors are at risk of being poisoned or inhibited. This leaves workers on their shifts unprotected. IR sensors are not susceptible to these conditions, so significantly enhance safety. 

Problems with IR sensors 

IR sensors do not measure hydrogen, and they usually don’t measure acetylene, ammonia of some complex solvents either except for some specialist sensor types. 

If nothing is done to prevent it, moisture can build up inside IR sensors on the optics scattering the IR light and causing a fault.  

The fail-safe nature of IR sensors, which automatically alert you to any fault, provides an additional layer of safety, and this results in a fault if there isn’t enough light getting through the system e.g., if the light is being scattered form the beam. 

IR sensors have very high resistance to interference or inhibition by other gases and are suitable for both high gas concentrations and use in inert (oxygen free) backgrounds where catalytic pellistor sensors would perform poorly. 

Products  

Our portable products such as Our Gas-Pro IR and Triple Plus+ help customers to detect potentially explosive gases where traditional, “pellistor,” catalytic sensors will struggle – especially in low oxygen or ‘poisoning’ environments. And allow for the measurement of hydrocarbons at both % LEL and % Volume ranges making this instrument ideal for tank and line purging applications. 

To explore more, visit our technical page for more information. 

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Gold Mining: What gas detection do I need? 

How is gold mined?

Gold is a rare substance equating to 3 parts per billion of the earth’s outer layer, with most of the world’s available gold coming from Australia. Gold, like iron, copper and lead, is a metal. There are two primary forms of gold mining, including open-cut and underground mining. Open mining involves earth-moving equipment to remove waste rock from the ore body above, and then mining is conducted from the remaining substance. This process requires waste and ore to be struck at high volumes to break the waste and ore into sizes suitable for handling and transportation to both waste dumps and ore crushers. The other form of gold mining is the more traditional underground mining method. This is where vertical shafts and spiral tunnels transport workers and equipment into and out of the mine, providing ventilation and hauling the waste rock and ore to the surface.

Gas detection in mining

When relating to gas detection, the process of health and safety within mines has developed considerably over the past century, from morphing from the crude usage of methane wick wall testing, singing canaries and flame safety to modern-day gas detection technologies and processes as we know them. Ensuring the correct type of detection equipment is utilised, whether fixed or portable, before entering these spaces. Proper equipment utilisation will ensure gas levels are accurately monitored, and workers are alerted to dangerous concentrations within the atmosphere at the earliest opportunity.

What are the gas hazards and what are the dangers?

The dangers those working within the mining industry face several potential occupational hazards and diseases, and the possibility of fatal injury. Therefore, understanding the environments and hazards, they may be exposed to is important.

Oxygen (O2)

Oxygen (O2), usually present in the air at 20.9%, is essential to human life. There are three main reasons why oxygen poses a threat to workers within the mining industry. These include oxygen deficiencies or enrichment, as too little oxygen can prevent the human body from functioning leading to the worker losing consciousness. Unless the oxygen level can be restored to an average level, the worker is at risk of potential death. An atmosphere is deficient when the concentration of O2 is less than 19.5%. Consequently, an environment with too much oxygen is equally dangerous as this constitutes a greatly increased risk of fire and explosion. This is considered when the concentration level of O2 is over 23.5%

Carbon Monoxide (CO)

In some cases, high concentrations of Carbon Monoxide (CO) may be present. Environments that this may occur include a house fire, therefore the fire service are at risk of CO poisoning. In this environment there can be as much as 12.5% CO in the air which when the carbon monoxide rises to the ceiling with other combustion products and when the concentration hits 12.5% by volume this will only lead to one thing, called a flashover. This is when the whole lot ignites as a fuel. Apart from items falling on the fire service, this is one of the most extreme dangers they face when working inside a burning building. Due to the characteristics of CO being so hard to identify, I.e., colourless, odourless, tasteless, poisonous gas, it may take time for you to realise that you have CO poisoning. The effects of CO can be dangerous, this is because CO prevents the blood system from effectively carrying oxygen around the body, specifically to vital organs such as the heart and brain. High doses of CO, therefore, can cause death from asphyxiation or lack of oxygen to the brain. According to statistics from the Department of Health, the most common indication of CO poisoning is that of a headache with 90% of patients reporting this as a symptom, with 50% reporting nausea and vomiting, as well as vertigo. With confusion/changes in consciousness, and weakness accounting for 30% and 20% of reports.

Hydrogen sulphide (H2S)

Hydrogen sulphide (H2S) is a colourless, flammable gas with a characteristic odour of rotten eggs. Skin and eye contact may occur. However, the nervous system and cardiovascular system are most affected by hydrogen sulphide, which can lead to a range of symptoms. Single exposures to high concentrations may rapidly cause breathing difficulties and death.

Sulphur dioxide (SO2)

Sulphur dioxide (SO2) can cause several harmful effects on the respiratory systems, in particular the lung. It can also cause skin irritation. Skin contact with (SO2) causes stinging pain, redness of the skin and blisters. Skin contact with compressed gas or liquid can cause frostbite. Eye contact causes watering eyes and, in severe cases, blindness can occur.

Methane (CH4)

Methane (CH4) is a colourless, highly flammable gas with a primary component being that of natural gas. High levels of (CH4) can reduce the amount of oxygen breathed from the air, which can result in mood changes, slurred speech, vision problems, memory loss, nausea, vomiting, facial flushing and headache. In severe cases, there may be changes in breathing and heart rate, balance problems, numbness, and unconsciousness. Although, if exposure is for a longer period, it can result in fatality.

Hydrogen (H2)

Hydrogen Gas is a colourless, odourless, and tasteless gas which is lighter than air. As it is lighter than air this means it float higher than our atmosphere, meaning it is not naturally found, but instead must be created. Hydrogen poses a fire or explosion risk as well as an inhalation risk. High concentrations of this gas can cause an oxygen-deficient environment. Individuals breathing such an atmosphere may experience symptoms which include headaches, ringing in ears, dizziness, drowsiness, unconsciousness, nausea, vomiting and depression of all the senses

Ammonia (NH3)

Ammonia (NH3) is one of the most widely used chemicals globally that is produced both in the human body and in nature. Although it is naturally created (NH3) is corrosive which poses a serve concern for health. High exposure within the air can result in immediate burning to the eyes, nose, throat and respiratory tract. Serve cases can result in blindness.

Other gas risks

Whilst Hydrogen Cyanide (HCN) doesn’t persist within the environment, improper storage, handling and waste management can pose severe risk to human health as well as effects on the environment. Cyanide interferes with human respiration at cellular levels that can cause serve and acute effects, including rapid breathing, tremors, asphyxiation.

Diesel particulate exposure can occur in underground mines as a result of diesel-powered mobile equipment used for drilling and haulage. Although control measures include the use of low sulphur diesel fuel, engine maintenance and ventilation, health implication includes excess risk of lung cancer.

Products that can help to protect yourself

Crowcon provide a range of gas detection including both portable and fixed products all of which are suitable for gas detection within the mining industry.

To find out more visit our industry page here.

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Our Partnership with Altitude Safety

Background

Altitude Safety has developed into one of the UK’s leading Confined Space and Site Safety Equipment suppliers. Supplying a product portfolio of over 10,000 products from the leading global manufacturers and with their dedicated fleet, Altitude Safety can deliver your safety solutions nationwide. Altitude Safety is part of the Citrus Group and has a client base of more than 35,000, thereby offering truly extensive and multifaceted provision. The Group aims to keep focused on Safety Equipment, Education and Training whilst also providing an effective and complete safety and training solution trusted by industries worldwide.

Views on Gas Detection

Providing both portable and fixed systems allows Altitude Safety’s customers to have a full solution option best suited to their needs and requirements. In regard to portable gas detection being a critical piece of safety equipment, Altitude Safety put customers at the forefront of gas detection, providing equipment in gas detection that not only protects their customers plants and processes but, more importantly, helps to prevent injury, thereby helping to ensure the health, safety, and wellbeing of its workers. Also, with the supply of fixed gas detection, Altitude Safety can offer its customers a complete turnkey solution for both new and replacement systems. Altitude Safety ensures the customers’ requirements through complete site surveys to provide advice on the best location of sensor heads, cable runs, and control panels. Whilst also offering a complete service from supply, installation, commissioning, and ongoing service/calibration contracts.

Maintaining and servicing safety products is key to ensuring that it remains in tip-top condition and ultimately works correctly at the critical time. Their manufacture approved service centre is operated via a team of dedicated and manufacturer-trained technicians. From receipt into our warehouse, Altitude Safety prides itself in being meticulously careful with the products ensuring that they are maintained, serviced and packaged correctly, ready for their customers to get back to operating as soon as possible.

Working with Crowcon

Through continuous communication of knowledge and expertise with Altitude Safety, our partnership has allowed for the supply of gas detection instruments for those working in the confined space and utility industries. “Our partnership with Crowcon has allowed us to provide a full turnkey solution for our customers and qualified service centres. We can provide a critical safety product to a range of industries, environments and workers to ensure safety for those involved”.

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Our Partnership with Hatech Gasdetectietechniek B.V.

Service providers are vital in supplying products and solution services to customers. However, they also provide customers with a range of knowledge and expertise to ensure they supply their customers with the correct equipment.

Background

Founded in 1994 and located in Raamsdonksveer, North Brabant, Hatech Gasdetectietechniek B.V. are a gas detection specialist. With over 25 years of experience, Hatech is the biggest service provider in the Netherlands, operating as a seven-person organisation and supply gas detection for the office, workshop, factory, plants, offshore, biogas or any other industrial environment. Hatech supply a wide range of gas detection products, from portable devices to complete fixed setups and customised installations. In addition to the supply of gas detection, Hatech is also a ‘one-stop shop’ as they issue calibration, service and supply rental of gas detection equipment.

Views on Gas Detection

Gas detection is a crucial piece of safety equipment for those who work in hazardous environments; therefore, supplying the correct equipment for the job is vital. Hatech ensures they provide the knowledge and understanding to enable their customers to understand and know the equipment they are buying correctly. Hatech issues tailor-made advice that ensures they know what application and who will be entering these environments to ensure that they offer the most suitable solution for your gas detection application.

Working with Crowcon

A 15-year partnership and continued communication have allowed Hatech to supply their customers with a gas detection solution. Although Hatech Gasdetectietechniek is based in the Netherlands, our partnership provides them with a short lead time allowing for a quick turnaround in products. Hatech is an official service centre for portable devices and supplying service engineers for fixed products. “Crowcon detectors are a premier gas detection solution that is simple to operate, with a complete sales and service team. Our partnership has provided our customers with new technology and the knowledge and understanding allowing for the correct equipment for the right application.”

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Our Partnership with Tyco (Johnson Controls)

Background 

Johnson Controls has over 120 years’ experience in providing complete life safety to the oil and gas industries world-wide helping to provide 90% of the world’s top fifty oil and gas companies. Merging with Tyco in 2018 they now provide a full turn-key solution for the global marine and navy industries. The merge has allowed for the protection of over 80% of the vessels at sea for all types of assets and facilities including fixed and portable devices. Johnson Controls also supply gas detection to the renewable industry.

Views on Gas Detection 

Johnson Controls is uniquely positioned to offer comprehensive and integrated solutions for a wide range of proven products and systems across several industries and applications. Johnson Controls have a culture that focuses on innovation and continuous improvement which in turn helps to us to solve current challenges whilst constantly looking to ‘What’s next’. As gas detection is an essential instrument for many workers within the oil and gas and marine industries, providing honestly and transparency is key as well as upholding the highest standards of integrity and honour in the commitments they make, ensure that their customers are given a solution that not only solves their pain but also protects their workers.  

Working with Crowcon 

Through continuous communication, our partnership with Johnson Controls has allowed them to provide honesty and transparency to their customers. This partnership has allowed Johnson Controls to reach a variety of industries and applications. Although previously our partnership has predominately been focused on our portable product range, future hopes will be focussed on our fixed product range, of which will allow Johnson Controls to expand their customer base as well as providing a solution to a wider audience. “Our partnership with Crowcon has allowed us to offer a solution to all customers, ensuring that those who we supply equipment to are protected.”  

Service, calibration and hire

With 25 years’ experience, Johnson Controls are experts in the service and calibration of our products in both their Aberdeen and Great Yarmouth offices. Johnson controls understand the need for gas detection therefore a fast turnaround is a must. Johnson controls not only distributes, services and calibrate our products but they also offer portable product hire in both locations.

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What causes Hydrocarbon Fires?  

Hydrocarbon fires are caused by fuels containing carbon being burned in oxygen or air. Most fuels contain significant levels of carbon, including paper, petrol, and methane – as examples of solid, liquid or gaseous fuels – hence hydrocarbon fires. 

For there to be an explosion risk there needs to be at least 4.4% methane in air or 1.7% propane, but for solvents as little as 0.8 to 1.0% of the air being displaced can be enough to create a fuel air mix that will explode violently on contact with any spark.

Dangers associated with hydrocarbon fires

Hydrocarbon fires are considered highly dangerous when compared to fires that have ignited as a result of simple combustibles, as these fires have the capacity to burn at a larger scale as well as also having the potential to trigger an explosion if the fluids released cannot be controlled or contained. Therefore, these fires pose a dangerous threat to anyone who works in a high-risk area, the dangers include energy related dangers such as burning, incineration of surrounding objects. This is a danger due to the ability that the fires can grow quickly, and that heat can be conducted, converted and radiated to new sources of fuel causing secondary fires. 

Toxic hazards may be present in combustion products, for example, carbon monoxide (CO), hydrogen cyanide (HCN), hydrochloric acid (HCL), nitrogen dioxide (NO2) and various polycyclic aromatic hydrocarbons (PAH) compounds are dangerous for those working in these environments. CO uses the oxygen that is used to transport the red blood cells around the body, at least temporarily, impairing the body’s ability to transport oxygen from our lungs to the cells that need it. HCN adds to this problem by inhibiting the enzyme that tells the red blood cells to let go of the oxygen they have where it is needed – further inhibiting the body’s ability to get the oxygen to the cells that need it. HCL is a generally an acidic compound that is created through overheated cables. This is harmful to the body if ingested as it affects the lining of the mouth, nose, throat, airways, eyes, and lungs. NO2 is created in high temperature combustion and that can cause damage to the human respiratory tract and increase a person’s vulnerability to and in some cases lead to asthma attacks. PAH’s affects the body over a longer period of time, with serve cases leading to cancers and other illnesses. 

We can look up the relevant health levels accepted as workplace safety limits for healthy workers within Europe and the permissible exposure limits for the United States. This gives us a 15-minute time weighted average concentration and an 8-hour time weighted average concentration. 

For the gases these are: 

Gas  STEL (15-minute TWA)  LTEL (8-hour TWA)  LTEL (8hr TWA) 
CO  100ppm  20ppm  50ppm 
NO2  1ppm  0.5ppm  5 Ceiling Limit 
HCL  1ppm  5ppm  5 Ceiling Limit 
HCN  0.9ppm  4.5ppm  10ppm 

The different concentrations represent the different gas risks, with lower numbers needed for more dangerous situations. Fortunately, the EU has worked it all out for us and turned it into their EH40 standard. 

Ways of protecting ourselves

We can take steps to ensure we do not suffer from exposure to fires or their unwanted combustion products. Firstly of course, we can adhere to all fire safety measures, as is the law. Secondly, we can take a pro-active approach and not let potential fuel sources accumulate. Lastly, we can detect and warn of the presence of combustion products using appropriate gas detection equipment. 

Crowcon product solutions

Crowcon provides a range of equipment capable of detecting fuels and the combustion products described above. Our PID products detect solids and liquid-based fuels once they are airborne, as either hydrocarbons on dust particles or solvent vapours. This equipment includes our Gas–Pro portable. The gases can be detected by our Gasman single gas, T3 multi gas and Gas-Pro multi gas pumped portable products, and our Xgard, Xgard Bright and Xgard IQ fixed products – each of which has the capability of detecting all the gases mentioned. 

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Changes to Workplace Exposure Limits (WELs)

What Are Work Place Exposure Limits?

Workplace exposure limits (WELs) provide a legal maximum level for harmful substances in order to control working conditions.

Directive and National Standards

The EU Directive 2017/164 establishes new ‘indicative occupational exposure limit values’ (IOELVs) for a number of toxic substances. The UK Health & Safety Executive (HSE) has decided to change UK statutory limits to reflect the new IOELVs. This decision by the HSE has been taken to comply with Articles 2 and 7 of the Directive requiring Member States to establish the new occupational exposure limit values within national standards by August 21st 2018.

Gas Detector Alarm Thresholds

The exposure limits defined in this Directive 2017/164 are based on the risks of personal exposure: a workers’ exposure to toxic substances over time. The limits (configured into gas detectors as ‘TWA alarm levels’) are expressed over two time periods:

  • STEL (short-term exposure limit): a 15 minute limit
  • LTEL (long-term exposure limit): an 8-hour limit

Portable (personal) monitors are intended to be worn by the user near to their breathing zone so that the instrument can measure their exposure to gas. The instruments TWA (time-weighted) alarms will therefore alert the user when their exposure exceeds the limits set within the national standards.

Portable monitors can also be configured with ‘instantaneous’ alarms which activate immediately when the gas concentration exceeds the threshold. There are no standards to define alarm levels for instantaneous alarms, and so we have these generally set at the same thresholds as the TWA alarms. Some of the new TWA thresholds are low enough to make frequent false alarms a significant problem if they were also adopted for the instantaneous alarm setting. Therefore, new portable instruments will retain the current instantaneous alarm thresholds.

Fixed gas detectors only utilise ‘instantaneous’ alarms as they are not worn by the user and therefore cannot measure an individuals’ exposure to gas over time. Alarm levels for fixed detectors are often based on the TWA alarms as these are the only published guidelines. HSE document RR973 (Review of alarm setting for toxic gas and oxygen detectors) provides guidance on setting appropriate alarm levels for fixed detectors in consideration of site conditions and risk assessment. In some applications where there may be a background of gas it may be appropriate for fixed detector alarm levels to be set higher than those listed in EH40 to prevent repeated false alarms.

Re-configuration of Gas Detector Alarm Thresholds

Users of portable gas detectors who choose to adjust their instrument alarm thresholds to align with the Directive can easily do-so using a variety of accessories available from Crowcon. For full details of calibration and configuration accessories visit the product pages at www.crowcon.com.

Other documents you may find useful:

http://www.hse.gov.uk/pubns/priced/eh40.pdf

http://www.hse.gov.uk/research/rrhtm/rr973.html

 

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