Measurement Services
How to Measure Radon Gas
Three different technologies to meet every need: from the rapid test of a few days to the annual certification mandatory by law.
Radon Detectors and Dosimeters: The 3 Techniques
There is no single instrument for everything. Compare costs and features to choose the right detector.
1. Rapid Test (E-Perm)
What is it: An "electret" chamber sensitive to electrical charges.
What it does: Tells you in 2-7 days if there is high Radon.
Cost: Economical.
When to use it: If you are buying a house and want a quick check, or if you have done work and want to verify immediately if it works.
2. Annual Test (CR-39)
What is it: A small special plastic disk in a protective shell.
What it does: Records Radon for 6-12 months.
Cost: Very low (a few dozen euros).
When to use it: For LEGAL OBLIGATION (companies, schools) or if you want absolute certainty of the annual average at home.
3. Active Monitor (Electronic)
What is it: A digital instrument that draws a graph.
What it does: Measures Radon hour by hour, day and night.
Cost: Medium-High (Rental/Purchase).
When to use it: If you want to understand when Radon enters (e.g., at night or when it rains) and study the phenomenon in detail.
CR-39 Passive Dosimetry
The Regulatory Gold Standard
Operating Principle
CR-39 is a transparent plastic optical polymer, extremely sensitive to high-energy alpha particles. When Radon gas decays in the surrounding air, it emits alpha particles that strike the surface of the CR-39, breaking polymer chains and leaving microscopic latent traces ("tracks"). It is a purely physical process that requires no batteries or electrical power.
Certified Laboratory Analysis
After the exposure period (typically 12 months for legal certification), the dosimeter is sealed and sent to the laboratory. Here it undergoes chemical etching with caustic soda which enlarges the tracks making them visible under an optical microscope. An automated system counts the number of tracks per unit area: this value is directly proportional to the average Radon concentration breathed during the year.
Why it is Law (D.Lgs 101/2020)
Radon concentration fluctuates enormously (it rises at night, falls during the day, changes in summer and winter). An instantaneous measurement would make little sanitary sense. The CR-39 is the only economical and robust system capable of "integrating" exposure over an entire solar year, providing the real average value needed to assess health risk and remediation obligation according to Italian regulations.
Electret Dosimetry (E-Perm)
The Professional Rapid Solution
Ion Chamber Technology
The E-Perm system (Electret Passive Environmental Radon Monitor) consists of a conductive plastic ion chamber and an "electret": a Teflon disk electrostatically charged with a stable potential (e.g., 700V). When Radon enters the chamber and decays, it ionizes the internal air. The negative ions produced are attracted to the surface of the positively charged electret, reducing its surface charge proportionally to the gas concentration.
Immediate Electronic Reading at Low Cost
The measurement consists of reading the electret voltage BEFORE and AFTER exposure with a dedicated digital reader. The potential difference (delta V), divided by the exposure days and corrected for gamma background, provides the average concentration. The huge advantage over CR-39 is speed: reliable results are obtained in just 2-7 days, without having to wait for chemical laboratory analyses.
Ideal for Screening and Diagnosis
This speed makes it irreplaceable for pre-purchase real estate checks (where you cannot wait a year), for post-remediation checks (to see if the intervention worked immediately), or for rapid mapping of large buildings. It is a method approved by the US EPA and widely used for preliminary investigations.
Continuous Active Monitoring
Advanced Diagnostics
Real-Time Electronic Sensors
Unlike passive dosimeters that only give a final number (the average), active monitors are true portable laboratories. They sample the air continuously (e.g., every hour) using silicon photodiode sensors or pulsed ionization chambers. This allows generating a "movie" of the Radon trend over time, not just a static "photograph".
Environmental Correlations and Diagnosis
They allow superimposing the Radon graph with those of Temperature, Pressure, and Humidity. This reveals if Radon enters via "stack effect" (higher in winter or at night) or if it is pushed by rain. This information is gold for the remediation designer: understanding THE CAUSE of entry allows targeting the intervention (e.g., sealing vs. depressurization) saving unnecessary costs.
The Professional's Tool
The active monitor is the Radon expert's stethoscope. It is used for short diagnoses (48-96 hours) to identify entry points (sniffing), verify the effectiveness of a newly installed ventilation system, or monitor high-risk environments in real-time.
Which instrument is right for me?
Choose based on YOUR goal, not the technology.Do you need to comply with legal obligations?
If you are an Employer, a Principal, or need to obtain occupancy certification for a basement, YOU MUST use the annual CR-39. The law (Legislative Decree 101/2020) requires measurement averaged over 12 months to have legal validity. Rapid tests are not valid in this case.
Do you just want peace of mind at home?
You can start with a Rapid Test (E-Perm) to rule out serious problems. However, if you want mathematical certainty, the advice is always the annual CR-39, because Radon changes a lot between summer and winter.
Are you planning remediation?
Here you need the Active Monitor. The technician needs to see how Radon varies minute by minute to understand where it enters (crawl space, cracks, pipes) and design the intervention tailored to you.
How the service works
No complications: here is what happens when you contact us.
1. We send you the Kit (or we come to you)
For most cases, we ship the kit via courier. It contains the dosimeters and instructions. For large companies or schools, we send a specialized technician to position them correctly.
2. You position the dosimeters
It is as easy as placing an ornament. Put them on a shelf in the living room or bedroom, away from windows. Mark the start date on a sheet.
3. Wait for the end of the test
Leave them there for the established time (a few days or a year). They make no noise, require no power outlets, and are not disturbing. You will forget about them.
4. You send them back to us
At the end, put them in the provided envelope and send them back to us. We analyze them in the laboratory and send you the Official Certificate via email.
Quality Guarantee and Legal Validity
Why our certificate matters.
The "Piece of Paper" that counts
When an official document is needed, form is substance. A radon measurement certificate has value only if issued by an accredited laboratory, with a documented chain of custody and procedures compliant with current regulations.ISO 17025 Accredited Laboratory
We do not rely on generic supermarket kits or uncertified laboratories. All analyses of CR-39 dosimeters are performed at an ISO 17025 accredited laboratory by Accredia, the Italian accreditation body recognized by the State. This certification guarantees that analytical procedures, instrumentation, and personnel respect international standards of quality and technical competence. Practically, this means that the result of your measurement is legally valid and recognized by ASL, ARPA, notaries, and courts for real estate sales, occupancy certifications, and fulfillments provided by Legislative Decree 101/2020 (National Regulations). The laboratory also participates in international interlaboratory comparison programs (proficiency testing) organized by bodies like the German BfS and British PHE, to constantly verify the accuracy and repeatability of alpha track counts.
Rigorous and Traceable Chain of Custody
Every single dosimeter we ship is identified by a unique barcode associated with the production lot serial number. We digitally track every critical step: the packaging date, shipment from our headquarters with courier tracking number, reception date at your address (confirmed by delivery signature), and finally the collection and return to the laboratory for analysis. This documented and uninterrupted chain of custody guarantees that the issued certificate corresponds exactly and uniquely to the device that was exposed in your environment for the entire measurement period. There is no possibility of error, exchange, or confusion between samples of different customers. The final test report reports all these references, making it a document opposable to third parties and usable in court.
Radon in Water and Soil
Sometimes the problem is not in the air you breathe at home, but comes from below: from the soil on which the house is built or from the water coming out of the taps. These specialized analyses allow intercepting radon at the source, before it becomes an indoor problem.Radon Analysis in Soil (Soil Gas Radon)
Are you about to build a new house or need to evaluate building land? Measuring radon concentration in soil interstitial gas (soil gas) BEFORE laying foundations is the only scientifically correct approach to design anti-radon protections in a targeted way. We use metal probes driven into the ground at variable depths (generally between 50 cm and 1 meter, at the scheduled foundation level) connected to sampling pumps and active monitors. The gas is aspirated slowly to avoid contamination with outside air and analyzed in real-time. This type of investigation is particularly important in priority areas identified by the National Radon Plan and regional regulations. Intervening during the project phase — with anti-radon membranes, ventilated crawl spaces, or soil depressurization systems — costs a fraction compared to having to remediate a house already built.
Radon Analysis in Groundwater and Wells
Radon is not just an indoor air problem: if your home is served by a private well or a natural spring, radon gas dissolved in water can represent a significant entry route. Every time you turn on a tap — and especially during a hot shower, where aeration and misting favor gas release — radon passes from water to the air you breathe. We analyze a sample of your water using the liquid scintillation technique or with E-Perm devices specifically designed for measurements in water. The result will tell you if the concentration is within standard or if it is necessary to install activated carbon filters, aerators, or degassing systems before entry into the domestic system. The analysis is rapid and non-invasive: just a single sample taken according to our instructions.
For Professionals
Sales, Rental, and Technical Support
Are you a surveyor, an engineer, or a Safety Officer? Beyond simple measurement, we support professionals in the diagnostic and remediation phase. We can supply or rent you professional instrumentation (certified active monitors, sampling pumps, soil gas kits) to perform your diagnoses independently. We also offer rapid training courses on instrument use, assistance in interpreting graphs, and specialized technical consultation for the design of remediation systems (e.g., soil depressurization, forced crawl space ventilation), guaranteeing the achievement of regulatory objectives with efficient and durable solutions.
FAQ
Frequently Asked Questions
Detailed answers to the most common doubts about measurement.
Can I use rapid tests for my company?
Are dosimeters dangerous or radioactive?
What happens if I reset or turn off the dosimeter?
Does Radon vary between day and night?
Should I open or close the windows during the test?
How many dosimeters are needed for a house?
If the test is negative, am I safe forever?
How long is the certificate valid?
Can I move the dosimeter from one room to another?
What do the instructions contain?
Not sure which to choose?
Call us or write to us. We will advise you on the right solution for your case (private or company) in a few minutes.