The importance of annual calibration for your flue gas analyser/combustion analyzer 

For many heating engineers, the flue gas analyser/combustion analyzer is vital kit; so much so, that most would have problems working without one. However, calibration and servicing generally require the engineer to send the analyser away for a while. That’s why, when the annual calibration date comes around again, some find themselves tempted to put it off, just for a while … 

Please ignore that temptation. It is absolutely vital to get your flue gas analyser calibrated every year, and failing to do so could cost you your job – or worse. Prompt annual calibration is simply not negotiable, and in this blog post we’ll explore the reasons why. 

Annual certification required 

A flue gas analyser is safety equipment and its accuracy may be – quite literally – a matter of life or death. The  sensors inside flue gas analysers react with the gasses they detect and degrade slightly over time. Compiled over the course of a years active use, the degradation can lead to inaccuracies in the readingsAdditionally, like any equipment, things can go wrong and parts can fail; that’s why all flue gas analyser manufacturers require an annual certificate of calibration, and the impact of not having one can be legally, financially and personally disastrous. 

Imagine, for example, that an accident has occurred and somebody or something has been harmed because your flue gas analyser failed to detect an issue. If that analyser was uncertified and had not been calibrated within the time period required (which would be easy to ascertain, since gas reports have the relevant times and dates printed on them), then you and/or your employer may be held criminally and civilly liable for this, having failed to exercise your duty of care to your client.  

That’s why, if your combustion analyzer is showing any signs of failure, or if your annual calibration is due, you need to book it in promptly. 

What about costs? 

Sometimes, engineers are tempted to put off calibration for fear of the costs. And yes, there may be charges involved due to damage or wear and tear: but what price do you put on safety (both the safety of the people you serve the security of your own job or business?) If cost is an issue, there may be ways to mitigate this. Manufacturers know that calibration is a recurring cost and some offer pre-pay options to make this easier to manage; some offer pre-pay options for parts as well. If you’re not sure whether this is the case for your device, it is worth talking to the manufacturer because the savings can be substantial. 

What happens during calibration? 

During its annual service and calibration, your flue gas analyser will be checked over and any components (for example, an oxygen sensor) will be replaced as required. A known concentration of certified test gas will be passed into the analyser and the instruments software will be adjusted to make sure it takes into account any drop off in sensor response and to ensure the analyser responds appropriately to all gases across the range of detection.  

Don’t wait – calibrate 

As you can see, calibration and any associated changes are vital to the functioning of your analyser, so you should never postpone or overlook your annual calibration: in fact, you must not use a flue gas analyser at all, once the previous calibration has expired. This applies however often (or not) you use it: the risks are the same.  

To find out more, visit our dedicated HVAC page.

Our Partnership with Acutest

Background

Acutest have established themselves as a leading player in test instrument supply, repair and calibration, asset management and bespoke training services. Acutest are a complete solution provider who match to each customer’s need. Their team of external account managers support customers with onsite product demonstration as part of the solution identification process. Serving across sectors including utilities (distribution network operators), sole traders, public sector and white goods. Acutest are a trusted partner to many sectors, who have a diverse customer base including the utilities, street works and rail sectors, facilities maintenance teams, manufacturing, processing and industrial plants as well as individual contractors and electricians.

View on Flue Gas Analysers

Providing workers within these sectors with the correct equipment is vital, therefore providing these workers with an essential tool is key at Acutest. This tool is used every day; therefore, Anton by Crowcon flue gas analysers provide an easy-to-use tool that detects CO (Carbon Monoxide) and NO (Nitrogen Oxide).

Working with Crowcon

Acutest Calibration Services

Acutest have been a long-term partner in which our gas analysers prevent users from having to store, charge, carry, calibrate and transport multiple devices. Our equipment allows Acutest customers to conduct all critical test measurements with just one high performance, innovative solution. “Our partnership with Acutest has enabled them to supply their customers with a readily available, reliable product as well as customer support. Anton by Crowcon provide innovative tools for every engineer needs and has been a go to on many occasions.”

Sprint Pro on Biofuel Applications 

Unlike fossil fuels, biofuels are man-made fuels created using plant-based renewable resources often known as biomass. As biofuels are renewable, they help to reduce the net amount of CO2 entering the atmosphere from combustion-powered vehicles and other energy users. All petrol and diesel fuels sold in the UK are obliged to contain a certain percentage of biofuel (10% bio ethanol in petrol and 7% biodiesel in diesel) in order to help meet wider emissions targets. 

What is biofuel?  

Different from other renewable energy sources, biomass can be converted directly into liquid fuels known as biofuels. The two most familiar types of biofuels are ethanol and biodiesel, both of which are first-generation biofuel technology.  

Ethanol  

Ethanol (CH3CH2OH) is a renewable fuel that can be produced from a variety of plant materials, collectively known as biomass. Ethanol is an alcohol that is used as a blending agent to replace a percentage of gasoline, making a mixture. It has the added bonusses of reducing carbon monoxide and other smog-forming emissions.  

In the modern world where cleaner fuel is the future, the most common blend is E10 (10% ethanol, 90% gasoline), legally mandated as the composition of unleaded petrol in the UK from September 2021. Some modern vehicles have been designed to run on E85. This is a gasoline-ethanol blend containing between 51% and 85% ethanol, the exact composition being dependent on geography and the season. This is an alternative fuel with much higher ethanol ratio compared to that of regular gasoline. It is sold in approximately 2% of the filling stations in the United States, and overall, roughly 97% of gasoline in the United States contains some ethanol. 

Most of the ethanol is produced from plant starches and sugars, but development is continuing in technologies that would permit the use of cellulose and hemicellulose, a non-edible fibrous material that constitutes the bulk of plant matter, and there are now several commercial-scale cellulosic ethanol biorefineries currently operational in the United States. The common method for converting biomass into ethanol is through fermentation, when microorganisms (e.g., bacteria and yeast) metabolise plant sugars and produce ethanol. 

Biodiesel  

Biodiesel is a liquid fuel constructed from renewable sources, such as new and used vegetable oils as well as, animal fats. This type of liquid fuel is a cleaner-burning replacement for petroleum-based diesel fuel. Biodiesel is biodegradable and is made through the combination of alcohol and vegetable oil, animal fat, or recycled cooking grease. 

Similar to petroleum-derived diesel, biodiesel is used to fuel compression-ignition (diesel) engines. Biodiesel has the characteristics to be blended with petroleum diesel in any ratio, and then burned as fuel in modern diesel engines. This includes B100 which is pure biodiesel, as well as the most common blend, B20, which contains 20% biodiesel and 80% petroleum diesel. 

Are biofuels the future?  

Although biofuels are cleaner than previous fuels, it seems unlikely that biofuels will ever be a complete replacement for petrol and diesel, though they may bridge the gap from previous fuels to future fuels. This is mainly down to the Government aiming higher for the country to be completely carbon neutral by 2050, with electric cars key to removing tailpipe emissions completely, in which Biofuels could help reduce our carbon footprint for now.  

However, a more promising approach to biofuels could be that of synthetic fuels or eFuels. Petrol and diesel are known as ‘hydrocarbons’ as they contain a combination of hydrogen and carbon atoms that make up all oils. Whereas eFuels get their hydrogen from water and carbon from the air, through the combination into structures similar to that of petrol and diesel. Synthetic fuels can be created with renewable energy, and carbon captured during their creation can offset the CO2 emissions when they are burned. Current developments suggest that eFuels may have the potential to store energy that is generated via renewable sources during times of low demand. 

Sprint Pro on biofuel application 

The main requirement is that the oil filter kit is needed rather than the normal kit. The oil kit filter will last through many tests that would block most tighter weaves, but it is still highly effective at preventing moisture ingress into the flue gas analyser itself, where it would cause damage to pump and sensors. Many biofuels are catered for by the Sprint Pro efficiency and safety algorithms, and more will be added as their use becomes significant. Such algorithm updates occur automatically at the annual service as part of the calibration process, meaning the users of Sprint Pro are to some extent futureproofed against changes known and also as yet unknown. 

 

Why it’s Important to Measure Nitrogen Oxide (NOx)?

In the EU and UK it is now obligatory for all new domestic heating and plumbing products (rated up to 400 kw) to comply with maximum nitrogen oxide (NOx) emission levels. This is line with a great deal of international regulation: NOx emissions are controlled by law or regulation in many countries (including the US, Canada, Australia and Singapore) and these may vary further by sector (maritime and automotive may have their own specific codes and limits, for example). 

The regulation of NOx required because this gas is a major pollutant, associated with thousands of deaths worldwide through its effects – both direct and indirect – on human health. It has been associated with asthma in children, lung inflammation and a host of other respiratory disorders, as well as cardiovascular damage. NOx is dangerous to animals, plants and ecosystems and is a major constituent of acid rain and smog. 

Despite its singular name, NOx is actually a collective term for nitrogen oxides – a family of highly reactive and poisonous gases – which are produced when fossil fuels are burned. Although NOx pollution is a global problem, large cities are particularly badly affected through vehicle exhaust fumes and heating system emissions; around a third of any large city’s NOx pollution comes from heating. In addition, nitrogen dioxide reacts in sunlight with other gases (such as volatile organic compounds) to generate ozone, which is a greenhouse gas.  

Why measure NOx? 

Since NOx emissions are increasingly regulated, they must be measured to ensure compliance with relevant directives. The measurement of NOx from boilers and other domestic appliances is also carried out to check that these are running safely, and to ensure the owner/operator and those around them are not being exposed to excessive NOx. 

Measuring NOx with a flue gas analyser/combustion analyzer 

As well as having to meet the demands of regulation, the HVAC sector recognises the growing importance of NOx measurement due to the worldwide focus on sustainability and green issues, and awareness of its harmful effects on health. This is reflected in a growing market for combustion analyzers that calculate NOx (e.g. the Sprint Pro 5 and the Sprint Pro 6).  

In the short to medium term, demand for NOx measurement seems likely to increase; the reduction of NOx emissions is a key component of sustainability policies worldwide and HVAC engineers and designers are prioritising the design of better, cleaner forms of heating (which will have to be benchmarked, verified and maintained).  

Over time, highly efficient, ultra-low-NOx systems are likely to dominate, and the measurement of NOx will therefore become an increasingly important parameter and a more prominent part of day-to-day work in the HVAC sector. 

Our Sprint Pro 5 and 6 models come complete with dedicated NO sensors allowing for a range of NO and NOx measurement options

Reset & Recalibrate – A Guide to FGA Calibration

Ensuring your flue gas analyser (FGA) is regularly maintained goes without saying, however the hows and whys take a little more digging into. This article breaks down the calibration process and highlights handy tips and tricks for maintenance and best practice. 

The Act of Calibration 

Calibrating an FGA involves checking the sensors to ensure accurate measurement of a known concentration of certified calibration gas. To do this, the reading needs to be adjusted to match the gas concentration through an initial sensor calibration of the new or existing unit.

Next up is a calibration drift – this is done using existing instruments to bring the reading back after the drift occurs. Measuring the amount of drift in the gauge is a chance to see how far into inaccurate territory it has moved, and rule out measurement errors moving forward. 

Regularity is key

Sensors degrade over time with each sensor having a different life span of optimum operation, whether it is an electrochemical, catalytic bead and infra-red sensors. Regular calibration raises the gain levels and brings the sensor back in line to avoid dangerous incorrect readings. 

Once the sensor reaches a certain point it cannot be brought back into the correct position and this is the time when a new sensor needs to be installed. 

Explaining the calibration procedure 

The first step of the process is to set the device to calibration mode. This feeds a test gas of a known concentration onto the sensors to see how they respond. The gain levels are adjusted within the sensor to match the readings to the concentration fed in whilst mitigating drop off. 

The new settings are locked into the device’s firmware and a calibration report is produced, creating a PASS or FAIL result. 

Best Practice Tips and Tricks

Here are some best practice recommendations to help you maintain your FGA.

  • Clear out the water trap regularly – moisture is a by-product of combustion and can get sucked into the FGA when a test is undertaken. Water damage is the primary cause of damage in flue gas analysers, so it is imperative to check, empty and replace the unit’s inbuilt water traps and filters to protect from this.
  • Purge the device in clean air before powering down – noxious gases are drawn from the flue and passed over the sensors to gain a reading. After a test is completed and the system closes down some of that gas remains trapped inside. This can cause corrosion damage and shorten the life of the unit, so purging in clean air prior to shut down is a must.
  • Take inside to protect from cold weather conditions – to lessen the chances of condensation build up and water damage within your FGA make sure to remove the unit from your van overnight. This also reduces the risk of theft. 
  • Use approved chargers with outputs tailored for target device – non approved chargers cause damage to the battery and lessen charge retention, or even impairment to the battery and IC chips of the device itself.  
  • Check the devices’ probes and connector pipes – any splits or cracks in the rubber house will cause incorrect readings. Performing periodic checks on your hoses to ensure they are in good operating condition is a useful habit. 

All-Inclusive Service Options 

You have multiple options when sending your device off for it’s annual service and calibration:

Send it direct to us

Crowcon’s innovative Autocal jig system manages the end to end calibration process for Sprint Pro FGA’s. An out-of-calibration unit leads to errors in the combustion reports produced and could disrupt your day to day. 

Autocal servicing is easy. Simply bring your FGA to one of the DPD drop off locations, your unit will be inspected, tested and calibrated within two days and returned to you using DPD’s express return trackable option.

For more information please check out https://shop.crowcon.com/

Send it to your local store

Drop your device in to your local trade counter or specialist servicing centre at a time convenient to you and they will work with us to facilitate the annual calibration.
They will contact you to come and collect your device once the calibration is completed.

Why HVAC professionals are at risk from Carbon Monoxide – and how to manage it

Carbon Monoxide (CO) is an odourless, colourless and tasteless gas that is also highly toxic and potentially flammable (at higher levels: 10.9% Volume or 109,000ppm). It is produced by the incomplete combustion of fossil fuels such as wood, oil, coal, paraffin, LPG, petrol and natural gas. Many HVAC systems and units burn fossil fuels, so it’s not hard to see why HVAC professionals may be exposed to CO in their work. Perhaps you have, in the past, felt dizzy or nauseous, or had a headache during or after a job? In this blog post, we’ll look at CO and its effects, and consider how the risks can be managed.

How is CO generated?

As we have seen, CO is produced by incomplete combustion of fossil fuels. This generally happens where there is a general lack of maintenance, insufficient air – or the air is of insufficient quality – to allow complete combustion.

For example, the efficient combustion of natural gas generates carbon dioxide and water vapour. But if there is inadequate air where that combustion takes place, or if the air used for combustion becomes vitiated, combustion fails and produces soot and CO. If there is water vapour in the atmosphere, this can reduce the oxygen level still further and speed up CO production.

What are the dangers of CO?

Normally, the human body uses haemoglobin to transport oxygen via the bloodstream. However, it is easier for the haemoglobin to absorb and circulate CO than oxygen. Consequently, when there is CO around, danger arises because the body’s haemoglobin ‘prefers’ CO over oxygen. When the haemoglobin absorbs CO in this way, it becomes saturated with CO, which is promptly and efficiently transported to all parts of the body in the form of carboxyhaemoglobin.

This can cause a range of physical problems, depending on how much CO is in the air. For example:

200 parts per million (ppm) can cause headache in 2–3 hours.
400 ppm can cause headache and nausea in 1–2 hours, life threatening within 3 hours.
800 ppm can cause seizures, severe headaches and vomiting in under an hour, unconsciousness within 2 hours.
1,500 ppm can cause dizziness, nausea, and unconsciousness in under 20 minutes; death within 1 hour.
6,400 ppm can cause unconsciousness after two to three breaths; death within 15 minutes.

Why are HVAC workers at risk?

Some of the most common events in HVAC settings may lead to CO exposure, for example:

Working in confined spaces, such as basements or lofts.
Working on heating appliances that are malfunctioning, in a poor state of repair, and/or have broken or worn seals; blocked, cracked or collapsed flues and chimneys; allowing products of combustion to enter the working area.
Working on open-flued appliances, especially if the flue is spilling, ventilation is poor and/or the chimney is blocked.
Working on flue-less gas fires and/or cookers, especially where the room volume is of inadequate size and/or the ventilation is otherwise poor.

How much is too much?

The Health and Safety Executive (HSE) publishes a list of workplace exposure limits for many toxic substances, including CO. You can download the latest version free of charge from their website at www.hse.gov.uk/pubns/books/eh40.htm but at time of writing (November 2021) the limits for CO are:

Workplace Exposure Limit

Gas Formula CAS Number Long Term Exposure Limit
(8-hr TWA Reference Period)
Short Term Exposure Limit
(15-min Reference period)
Carbon monoxide CO 630-08-0 20ppm (parts per million) 100ppm (parts per million)

How can I stay safe and prove compliance?

The best way to protect yourself from the hazards of CO is be wearing a high quality, portable CO gas detector. Crowcon’s Clip for CO is a lightweight 93g personal gas detector that sounds at 90db alarm whenever the wearing is being exposed to 30 and 100 ppm CO. The Clip CO is a disposable portable gas detector that has a 2-year lifespan or a maximum of 2900 alarm minutes; whichever is sooner.