How Radonova provides optimal radon measurement quality

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Radonova has always strived to scrupulously respect the regulatory requirements of all the countries in which we carry out radon measurements to ensure our customers receive a high quality of service. We meticulously take care to maintain our ISO17025 accreditation, participate in inter-comparative tests, while methodically following the measurement protocols defined by various national authorities. At the same time, we impose rigorous and particularly demanding quality control protocols internally to guarantee the best possible continuity and quality of our products.

Selection of raw material

Radonova has several suppliers of CR39 plastic, so as not to risk any failure from one of the providers we are working with. This raw material is delivered to us in the form of batches from which we produce around 120 films ready to be introduced into our detectors.

After a first pre-etching step to clean the films, a smaller part of them are set aside to be tested. We place them under the microscope to count the number of alpha tracks already present on the film. The objective is to control the quality of the raw material supplied. The number of tracks measured must be below a certain value so that the films from the same batch can be placed on the assembly line.

Detector calibration

Once manufactured, 3% of the detectors are used for calibration exposures, which is a high value compared to some laboratories where 1% is the norm. This is one of the reasons why Radonova has industry leading quality in radon measurement. These detectors are sent to different national radiation chambers (PhE in England, BfS in Germany, SSM in Sweden and Bowser-Morner in the United States) where the calibration is performed. They are exposed to different radon levels in order to determine calibration factors representative of the typical values to which most detectors sent to our customers are exposed, but also to more extreme values in order to guarantee the effectiveness of the detectors in all situations.

The calibration factors used to determine the exposure of the detectors are calculated for batches of approximately 1000 to 2000 films.

Detector background calculation

Radonova also devotes a part of its production, 6% of the detectors, to calculate the unexposed background of the detectors. We basically calculate the average number of tracks which will have to be subtracted from the total number of tracks counted after the measurement. To do this, we etch and measure the films from the selected background detectors, just before the customer detectors are expected to be returned for analysis. In this way, we determine a proper background value for each batch of 120 films.
The typical background of a Radtrak2 detector is around 15 kBqh / m3 and the standard error of uncertainty is around 4 kBqh / m3.

In total, 12% of the CR-39 film produced and almost 10% of all detectors manufactured by Radonova will never arrive in our customers’ mailboxes. This requirement that we impose on  ourselves and which, alongside the various national requirements in this area, allows us to maintain a very high level of quality for our customers and enables us to maintain our position as the global leader in radon measurement.

How Radonova provides optimal radon measurement quality

New Builds – the importance of measuring for radon in soil

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When radon is being discussed, it frequently revolves around levels of radon in soil. This is not surprising. Radon leaking or being sucked from the ground is the cause of elevated indoor radon levels in 80 per cent of affected properties. However, it is important to note that radon content in the soil where the building is located, does not necessarily determine indoor radon levels. In most cases, the materials used to build the home, and the design of the ventilation system, influence the presence of radon in the dwelling. Builders and designers should always be mindful of radon when planning a new property.

If there are high levels of radon in the soil, a radon guard should be incorporated into the design of the home from the outset.

Radon content in different soil types

In order to manage potential radon issues in regard to new builds, you need to understand how radon is formed and where it exists. Radon is a decay product from the radioactive element Radium, which in turn is a decay product of Uranium, found naturally in soil. As radon is a gas it easily leaks from the soil into houses through tiny cracks in foundations and walls. However, concentrations vary, which affects radon levels in different types of soil. In some cases, high levels of radon naturally occur due to the precipitation of uranium and radium from groundwater.

Another important factor to consider is the shape of the mineral grains in the soil. Generally, radium-containing grains with a large exposed surface cause more radon. The surface size usually increases with a smaller grain size and with greater cracking in the grains. In addition, radon content in soil is affected by how it spreads from the ground to the atmosphere, which is controlled by the soil’s porosity, water content and winds. Therefore, radon levels are often weather dependent.

The only way to fully understand how much radon is in the soil is to measure. In order to minimize the impact of variable weather conditions, the measurement should be done at a depth of 0,8 – 1 meter. Two measurement methods are used to do this – digital and passive.

In the long term, it is more cost effective and efficient to have an accurate measurement from the start, especially in relation to new builds. Therefore, in terms of radon, make sure it is a consideration at an early stage. It pays off.

For more information about radon and radon measurement please visit 

Seasonal workers are crucial to Radonova’s operations  

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Radon measurement is largely seasonal, with May being the peak. But even from October, there are many days when thousands of detectors are sent to customers and then returned for analysis. To cope with the peaks across the year, seasonal staff play a pivotal role in Radonova’s ongoing operations. We had a chat with 25-year-old Melker Lindberg who is now finishing his first season at Radonova.  

What made you look for a job as a seasonal worker at Radonova?

A friend of the family has worked here for over a year and talked about the job and the work environment. He mentioned that extra staff would be needed for the high season. It sounded interesting work. After working at a retirement home for several years, I felt like doing something completely different.  

What has been your primary tasks?

I am part of the team that receives detectors that are sent back for analysis. After removing the contents from the packages, we scan the detectors into the system and remove the trace films. These are then set up in the carousels where they are prepared for etching, the next step in the process. After that, we work on the documentation. Although many steps and processes are electronic, there are still forms, Excel sheets and handwritten notes in the boxes which need to be actioned. That information needs to be collected, labelled, scanned, and transferred into the system. 

Are there things that has been more difficult than you expected?

Putting the boxes in the carousels can be tricky, something my colleagues warned me about right from the start. You have to stay focused. This is a particularly interesting challenge since I have ADHD. Having said that, things have gone well, partly thanks to the fact that you never staff the department alone. Which is good, it’s a bit like peeling potatoes with your friends. 

What is Radonova like as a workplace?

It is a relaxed workplace. Everybody gets on, which makes the working day go faster. I hadn’t really heard of radon measurement before I started here. After just one season, I feel I’ve learned a lot. For the fall, I have applied for a chef training course. If I am not accepted and stay in Uppsala, I look forward to working at Radonova next season. 


For more information about radon and radon measurement please visit  

Melker Lindberg

Five steps which guarantee a quality assured radon measurement

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Since the company’s inception, Radonova has prided itself on its industry leading quality procedures and processes in terms of radon measurement. Our measurement methods and methodologies are globally recognised and importantly adjusted for the individual requirements of every country. To date, we have delivered radon measurements to over 50 countries. Due to our efficient processes and high degree of digitalisation, we offer short delivery and analysis times across Europe and North America. 

So, how do we do this? There are five steps which are critical to ensuring quality assured radon measurements 


Radonova’s measurement methods are accredited in accordance with ISO/IEC 17025. Therefore, our measurement processes are continuously audited by an independent state body which has to be a member of the European AccreditationThis review is conducted annually and takes place on site for at least two days. We are also audited for impartiality, which is a requirement of ISO/IEC 17025. Consequentlythere is no self-interest for Radonova to demonstrate a certain measurement result. Read more about our accreditation here. 


Some countries require validation of their measurement process. This is normally done by submitting radon detectors for blind testing at a national authority where the detectors are exposed to different levels of radon. The detectors are then sent back to Radonova’s laboratory for analysis and a measurement result is produced. The result is then compared with the official value of the national authority. Here you can read about the results of our latest validation test.

Comparison tests

Radonova regularly participates in national and international comparison tests. In these tests, different radon laboratories contribute voluntarily and radon detectors from different suppliers are exposed at the same time to a radon content that participants aren’t aware of in advance. The results of the tests form the basis of Radonova’s accreditation. One of the most demanding comparison tests is the German federal authority BfS (Bundesamt für Strahlenschutz). Here you can read more about those particular results.

Customer control

Radonova’s customer tests are primarily conducted in the United States and Canada, which has a different approach to European quality testing in radon laboratories. For example, every tenth detector should have a “duplicate”. This means that there should be two radon detectors at 10% of the measuring point, and the results of the two detectors should be compared. By doing this, you can check the uniformity of the results from the measurement laboratory. In addition, accuracy is verified as customers who conduct multiple measurements are required to send 3% of their Radonova detectors to a test facility with specific reference values. This enables a blind test, where the customer is able to confirm that the measurement is reliable. Customers are also required to follow up and check on unexposed radon detectors “blanks”.

Internal tests

Each measurement includes at least two radon detectors that have been exposed in a calibration chamber with known radon content. By checking that these radon detectors display the correct results, we are able to quality assure our measurement process in the laboratory. 

Radonova receives excellent results from PHE for validation test

The importance of returning radon detectors correctly 

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At Radonova, high quality control standards and procedures are integral to our business. Therefore, it’s important to emphasise the significance of returning radon detectors in an appropriate manner to enable us to conduct precise measurements. To avoid inaccurate analysis values, “alpha-track” detectors such as Radtrak2, Rapidos and Duotrak, should generally not be returned in sealed bags. If the measurement time is less than 14 days, returning detectors in sealed bags comprimises industry standards. 

There is a good reason for this. Radon is adsorbed into the plastic bag which covers the detector, which can provide elevated values of up to 10-20%, if the measurement time has been too short. The longer the detector is in a sealed bag, the higher the deviation. This is especially true if the bag is small and is too close to the detector. 

Itwidely recognised that there is a risk of deviation when detectors are placed in sealed bags. We strongly recommend that bags should not be sealed when returned to usIt’s important that we get this message across so that the risk of error is reducedThe possibility of additional radon exposure during transport in unsealed bags is generally very low when compared to the risk of extra exposure if the bag is sealed, said Tryggve Rönnqvist, technical manager at Radonova Laboratories. 

For more information about radon and radon measurement visit

After the measuring time is completed detectors should be returned to your local hub who will handle the shipment back to the laboratory. 

If you need further help with returns, please contact our support

Short-term measurement

Instrument veteran driven by helping customers

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Fredrik Lindén has worked with radon measuring instruments for many years. When the radon measurement instrument division of Gammadata Instruments was acquired by Radonova in early 2019, Fredrik became part of a knowledgeable team in a very busy workshop. 

Close customer contact

I enjoy working at a company where my day-to-day activities are varied. They range from purchasing and inventory management to service, testing and production. Our instruments, and the services we offer, have a major impact on our customers’ operations. The service and support work we undertake requires particularly close customer contact. I find this stimulating and rewarding especially as we try to help our customers as quickly and efficiently as possible. The test phase is particularly gratifying as it concludes extensive work we have carried out in the workshop. We need this verification so that we can confirm that the instrument is field-ready. 

Freedom and responsibility encourage commitment

At Radonova, employees are given freedom and encouraged to act on their own initiative. In the workplace, it certainly feels like the goals of the individual and the company are alignedOur mantra is to continually improve to ensure that we offer partners, consumers and businesses exceptional radon measurement technologiesIf you are given freedom and responsibility, you also become more committedThis commitment is important as we work with relatively complex flows and procedures, so we need to be precise in every phase of the manufacturing process. 

Acquisition extended Radonova’s portfolio

By acquiring the radon measurement instrument division of GammadataRadonova added several advanced instruments and products to its portfolio, broadening its range of radon measurement technologiesBy offering a comprehensive program for radon measurementRadonova is responding to the global demand for safe and efficient radon measurements in homes and workplaces and strengthening its position as a world leader. 

Fredrik Lindén

Seasonal Peak for the Radonova Instrument Workshop

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The season for measuring ground radon is nearly upon us. This coincides with there being a sharp increase in the global demand for reliable radon instruments. For Fredrik Lindén and his colleagues at Radonova’s radon instrument production department, this equates to long days to fulfil customer requests.

”When assembling radon instruments we use state-of-the-art technology, but there is still a requirement for experience and craftsmanship. Our quality standards are very high, and every instrument that is manufactured here is tested for reliability to ensure it is field ready”, comments Fredrik Lindén.

Focus on timely, fast delivery

“To meet market demand, we are currently focusing on producing high volumes of MARKUS 10 – a portable, battery-powered instrument. We pride ourselves on our ability to deliver quickly, therefore we have to stay one step ahead of orders to ensure our stock is always able to accommodate future sales. Every instrument consists of numerous components, which means we have a very close relationship with our suppliers to ensure that all deadlines are met. Parts used to create our instruments are as important as each other, therefore high standards are expected throughout the supply chain”, continues Fredrik Lindén.

Robustness and ease of use

“For a product to be successful it needs to be robust, user-friendly and thoroughly tested – these are critical manufacturing factors for us. MARKUS 10 is a very good example. As you would expect, customers demand a reliable instrument and we always strive to exceed those expectations. Prior to each final assembly, we test all components based on our own high internal standards”, concludes Fredrik Lindén.

MARKUS 10 – an overview

Ground radon is the most common cause of elevated radon levels. MARKUS 10 is a precision instrument that measures high radon concentrations. It is portable and battery-powered. Attach the MARKUS 10 and hollow measurement probe to the ground and simply press a button to start measuring. Air is pumped through the probe tube into a chamber that detects radon daughters (fine solid particles which result from the radioactive decay of radon gas). Following the pumping phase, the measurement phase commences. The result is presented in the display after 12 minutes.

Seasonal Peak for the Radonova Instrument Workshop

Is radon only in basements

By Home, Measurement No Comments

Radon is completely odorless as well as being invisible. Because it is often found unexpectedly in basements, some people mistakenly believe that it only occurs in basements. This is a dangerous assumption that may damage your ability to protect your home if you are not careful.

Most commonly homes with basements are suspect for having higher radon levels. The fact that porous foundation walls allow radon gas to enter a home is no secret and with most basements containing a sump well, there are many access points from which radon can enter a home.

However, homes above a crawl space suffer the same fate. Whether your crawl space is a dirt crawl (unfinished), poured concrete (finished), or even lined with a protective barrier, radon can still enter your home. Additionally, with its closer proximity to the ground, the living areas of the home may be more susceptible to radon as it does not have the same amount of time to decay in a full basement prior to entering living areas.

Not to be forgotten, homes built on a slab are also at risk for high radon levels. As a matter of fact, homes built on a slab to not have the ‘buffer’ of a basement or crawl space to absorb and dissipate radon gas before it enters the living area of a home.

There is truly no single style of home that is not prone to radon gas and potentially highly dangerous levels.

What about new homes built with radon-resistant construction techniques?

As early as 1990 some homes have been built using radon-resistant materials and with pre-piped radon mitigation systems installed. Clean gravel “airflow layers”, vapor barriers, additional polyurethane caulking, and vent pipes are all widely used. However, as the name states, these techniques are radon ‘“resistant” and cannot fully remove the risk of a high radon level. Testing should still be performed to determine a homes radon level and in instances when a high radon level is present, some of the installed vent pipes used for passive radon reduction can easily be converted to an active system by a professional radon mitigation specialist.

Other sources of radon

If you have certain building materials in your home, then you need to worry about radon sources other than just below your home. In general, naturally occurring stone, rock and brick building materials always contain some Uranium that decays into Radon… These types of stone typically used for countertops and/or fireplace mantels may be a potential source of radon in your home. In most cases, the amount of radon immediate here is not a huge problem, but you need to know for sure.

In general, detection is your number one weapon against radon exposure. Make sure that you test your home regularly. This is the only ways that you will be able to protect yourself against the detrimental effects of radon in your home.

More informations about radon here.

Is radon only in basements

Radonova launches ROBIN2 – a professional radon sensor with high sensitivity

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Radonova Laboratories has launched ROBIN2, broadening its range of radon measurement technologies. The latest version of ROBIN is twice as sensitive as its predecessor and includes an improved response function for optimum compliance with rapid changes in radon levels.

ROBIN2 is a state-of-the-art radon sensor that can be deployed as a fixed installation in smart homes for monitoring and reducing radon levels. It can be mounted in all types of ventilation control units where there is a requirement to monitor radon levels. It can be easily connected to a controller, central unit, data logger, fan control system or PLC and is available in various formats.

The new response function improves measurement accuracy as radon levels fluctuate. This is due to its improved sensitivity, which reduces error at lower levels, otherwise it is limited by deteriorating statistics due to the pulse rate being too low. ROBIN2 has a new motherboard that is more insulated and weather resistant. ROBIN2 is available as a standard or industrial version which can be used for mining. The mining version has enhanced protection against dust and moisture and is optimized for underground measurements.

– I’m delighted that Radonova has enhanced the capabilities of ROBIN, which was the first radon sensor of its kind when it was first launched in 2016. ROBIN2 is without doubt a market-leading detector, due to its new response function and overall stability, said Dag Sedin, a senior advisor at Radonova, who was integral to ROBIN’s initial launch.

ROBIN2 is available now.

About ROBIN2

ROBIN2 measures the radon content of air in Bq/m³ and gives an analog output signal of 1-10V, proportional to the concentration of radon in the air. Compared to its predecessor, ROBIN2 has improved sensitivity and a larger and more efficient measuring chamber. The output signal is also more stable and more consistent with the real radon content variation. If required, the measurement range can be defined by the customer. The radon sensor is protected against electromagnetic interference and can be connected to a thyristor controller. The transducer is mountable without directional dependence and can be permanently installed in a room, ventilation shaft or air handling unit. The mining version has enhanced moisture protection and is built for an underground environment.

Additional features:
• Can measure accurately in both laminar and turbulent airflow
• High sensitivity to provide good time resolution
• Great flexibility and can be customized for OEM

For more information on ROBIN2 visit our dedicated website
For more information about radon and radon measurement visit our website


Radtrak2® – the world’s leading detector for long-term radon measurement

By Measurement No Comments

With over four million units sold globally, Radtrak2® is the most widely used radon detector for obtaining a reliable and accurate annual mean of radon levels in the home or workplace. Here is a short summary of its features:

Simple, foolproof assembly

The Radtrak2 unit is simple to construct. Included is a plastic top and bottom as well as a transparent plastic film made of CR-39 which is placed at the centre of the radon detector. During measurement, air leaks in through a very small gap between the top and the bottom. When the radon gas in the air decays to radon daughters, radioactive alpha particles are created. When these hit the transparent plastic film, tracks are formed in the film. After the measurement period, the number of tracks is used to calculate the radon level.

Environmentally friendly and robust technology

Since the detector is made of plastic and there are no moving parts, the radon detector rarely malfunctions. Radtrak2 can be used in very demanding environments and is not damaged if dropped on the floor. It is very difficult not to get an accurate measurement when using Radtrak2®. As long as you specify the start and stop times and use an accredited laboratory, you are guaranteed a reliable result. Radonova’s laboratory is always reusing the top and bottom parts of the detector, saving both cost and the environment. The only thing that is not reused is the transparent plastic film which is used for analysis.

Clean plastic film and fine-tuned, accredited analysis

When analysing the transparent plastic film (CR-39), there are certain requirements and stipulations which must be met. Firstly, a clean film must be used, placing demands on the manufacturing process of the detectors. Without an original pure film, it is not possible to analyse the number of tracks accurately after the measurement period. You must also take into account how much radon gas the plastic film has been exposed to before it is placed and sealed in the detector. Similarly, you must make allowances for the film being exposed to radon when it is sent back to the laboratory. Through a carefully controlled process, the laboratory calibrates various plastic films against a known radon source. Well-established routines are necessary to mitigate against error. Therefore, always purchase a radon detector from an ISO 17025 accredited laboratory such as Radonova. At Radonova, quality checks are continuous, ensuring that the radon measurement is correct.

Why measure for radon?

Every year around 230,000 people die of lung cancer caused by radon exposure. Radon gas is part of the element of the uranium decay chain and since uranium is found in many places in the earth’s crust, radon is found almost everywhere. High levels of radon can be found in regions which have a large concentration of rock or have a cool climate. The latter is due to the fact that radon gas levels are usually high in insulated houses that are heated. To be fully aware of radon levels, homeowners should always measure.

Most countries in the world require measurements that provide an annual mean, which usually entails a measurement period of over three months.