American Radon Services provides radon testing in Aldie, Alexandria, Arlington, Ashburn, Caroline, Culpeper, Fairfax, Fredericksburg, Gainesville, Haymarket, King George, Manassas, Orange, Richmond,Springfield, Spotsylvania, Stafford, Warrenton, Woodbridge and other parts of Virginia, Maryland and Washington DC.  Short Term Radon testing costs between $125-$150 and Long Term Radon testing costs between $150-$200.  Contact us today for a free no obligation quote.

The EPA recommends that you hire a qualified professional to test for radon when you are buying or selling a home.  Radon measurement testers are required to follow specific testing protocols.  If you hire a contractor to test your residence, protect yourself by hiring a qualified individual or company.  You can determine a service provider's qualifications to perform radon measurements or to mitigate your home in several ways.  Check with your state radon office.  Many states require radon professionals to be licensed, certified, or registered.  Most states can provide you with a list of knowledgeable radon service providers doing business in your area.  In states that don't regulate radon services, ask the contractor if they hold a professional proficiency or certification credential.  Here are the top two privately run national radon programs that are offering proficiency listings, accreditations and certifications in radon testing and mitigation. 

The National Radon Safety Board (NRSB)
Call: (866) 329-3474
Fax: (914) 345-1169

AARST - National Radon Proficiency Program
Call: (800) 269-4174 or (828) 890-4117
Fax: (828) 890-4161

There are Two General Ways to Test for Radon:

SHORT-TERM TESTING: The quickest way to test is with short-term tests.  Short-term tests are a "snap shot" and remain in your home from 2-7 days.   “Charcoal canisters,” “alpha track,” “electret ion chamber,” “continuous monitors,” and “charcoal liquid scintillation” detectors are most commonly used for short-term testing.  Because radon levels tend to vary from day to day and season to season, a short-term test is less likely than a long-term test to tell you your year-round average radon level.  If you need results quickly, however, a short-term test followed by a second short-term test may be used to decide whether to fix your home.  

LONG-TERM TESTING: Long-term tests remain in your home 90 days to 1-year. “Alpha track” and “electret” detectors are commonly used for this type of testing.  A long-term test captures the seasonal variations and lets you know what levels you are living with for an extended period of time.


We recommend testing for every home for radon no matter where you live.  Your should also test if you are buying or selling your home, before finishing the basement, after major remodeling projects and every 1 to 2 years if you have an existing mitigation system or if your last test was between 3.0 pCi/L and 4.0 pCi/L.

Radon levels change and depend on many factors like barometric pressure, wind speed and the time of year or season.  The short-term test is a snapshot over 3 or 4 days.  The long-term test averages the changes over 3 to 12 months.  The EPA recommends two short-term radon test kits side by side, or a second test immediately after the first one using an identical radon test device in the same location.


The EPA recommends that you test in the lowest level of the home, which is suitable for occupancy.  Some states and real estate practices require testing in the "lowest livable area" whether or not currently suitable for occupancy. This usually means radon testing in the basement.  

Closed-building conditions are required for test measurements lasting less than 90 days in order to stabilize the concentrations of radon and radon decay products and increase reproducibility of the measurement.  Other than a furnace or permanently installed heat recovery ventilators, external-internal air exchange systems should be turned off.  Close all windows and external doors at least 12 hours before beginning a short-term test.
We record the start time, date and typically will not conduct short-term tests during severe weather or sudden changes in barometric pressure, severe storms, or periods of high winds.  In the event we do, the length of the test will be extended for 24-48 hours.  The testing device will be placed at least 20 inches above the floor in a location where it will not be disturbed, away from drafts, high heat, high humidity, and exterior walls.  Some test kits can be hung a minimum of 12" below the ceiling and 3 to 5 ft. above the floor.  It's important to maintain closed-house conditions during the test but normal operation of the heating and cooling systems is acceptable during the test.

Listed below are brief descriptions of each of the 12-radon measurement methods and 3 radon decay product measurement methods that have been identified by the U.S. EPA and NRSB. 


1. AC - Activated Charcoal Adsorption
For this method, an airtight container with activated charcoal is opened in the area to be sampled and radon in the air adsorbs onto the charcoal granules. At the end of the sampling period, the container is sealed and may be sent to a laboratory for analysis. The gamma decay from the radon adsorbed to the charcoal is counted on a scintillation detector and a calculation based on calibration information is used to calculate the radon concentration at the sample site. Charcoal adsorption detectors, depending on design, are deployed from 2 to 7 days. Because charcoal allows continual adsorption and desorption of radon, the method does not give a true integrated measurement over the exposure time. Use of a diffusion barrier over the charcoal reduces the effects of drafts and high humidity.

2. AT - Alpha Track Detection (filtered)
For this method, the detector is a small piece of special plastic or film inside a small container. Air being tested diffuses through a filter covering a hole in the container. When alpha particles from radon and its decay products strike the detector, they cause damage tracks. At the end of the test the container is sealed and returned to a laboratory for reading.  The plastic or film detector is treated to enhance the damage tracks and then the tracks over a predetermined area are counted using a microscope or optical reader. The number of tracks per area counted is used to calculate the radon concentration of the site tested. Exposure of alpha track detectors is usually 3 to 12 months, but because they are true integrating devices, alpha track detectors may be exposed for shorter lengths of time when they are measuring higher radon concentrations. 

3. UT - Unfiltered Track Detection
The unfiltered alpha track detector operates on the same principle as the alpha track detector, except that there is no filter present to remove radon decay products and other alpha particle emitters. Without a filter, the concentration of radon decay products decaying within the "striking range" of the detector depends on the equilibrium ratio of radon decay products to radon present in the area being tested, not simply the concentration of radon. Unfiltered detectors that use cellulose nitrate film exhibit an energy dependency that causes radon decay products that plate out on the detector not to be recorded.  This phenomenon lessens, but does not totally compensate for the dependency of the calibration factor on equilibrium ratio. For this reason, EPA currently recommends that these devices not be used when the equilibrium fraction is less than 0.35 or greater than 0.60 without adjusting the calibration factor. 

4. LS - Charcoal Liquid Scintillation
This method employs a small vial containing activated charcoal for sampling the radon. After an exposure period of 2 to 7 days (depending on design) the vial is sealed and returned to a laboratory for analysis. While the adsorption of radon onto the charcoal is the same as for the AC method, analysis is accomplished by treating the charcoal with a scintillation fluid, then analyzing the fluid using a scintillation counter. The radon concentration of the sample site is determined by converting from counts per minute. 

5. CR - Continuous Radon Monitoring
This method category includes those devices that record real-time continuous measurements of radon gas. Air is either pumped or diffuses into a counting chamber. The counting chamber is typically a scintillation cell or ionization chamber. Scintillation counts are processed by electronics, and radon concentrations for predetermined intervals are stored in the instrument's memory or transmitted directly to a printer. 

6. EL - Electret Ion Chamber: Long-Term
For this method, an electrostatically charged disk detector (electret) is situated within a small container (ion chamber). During the measurement period, radon diffuses through a filter-covered opening in the chamber, where the ionization resulting from the decay of radon and its progeny reduces the voltage on the electret. A calibration factor relates the measured drop in voltage to the radon concentration. Variations in electret design determine whether detectors are appropriate for making long-term or short-term measurements. EL detectors may be deployed for 1 to 12 months. Since the electret-ion chambers are true integrating detectors, the EL type can be exposed at shorter intervals if radon levels are sufficiently high. 

7. ES - Electret Ion Chamber: Short-Term
For this method, an electrostatically charged disk detector (electret) is situated within a small container (ion chamber). During the measurement period, radon diffuses through a filter-covered opening in the chamber, where the ionization resulting from the decay of radon and its progeny reduces the voltage on the electret. A calibration factor relates the measured drop in voltage to the radon concentration. Variations in electret design determine whether detectors are appropriate for making long-term or short-term measurements. ES detectors may be deployed for 2 to 7 days. Since electret-ion chambers are true integrating detectors, the ES type can be exposed at longer intervals if radon levels are sufficiently low. 

8. GC - Grab Radon/Activated Charcoal
This method requires a skilled technician to sample radon by using a pump or a fan to draw air through a cartridge filled with activated charcoal. Depending on the cartridge design and airflow, sampling takes from 15 minutes to 1 hour. After sampling, the cartridge is placed in a sealed container and taken to a laboratory where analysis is approximately the same as for the AC or LS methods. 

9. GB - Grab Radon/Pump-Collapsible Bag
This method uses a sample bag made of material impervious to radon. At the sample site, a skilled technician using a portable pump fills the bag with air, then transports it to the laboratory for analysis. Usually, the analysis method is to transfer air from the bag to a scintillation cell and perform analysis in the manner described for the grab radon/scintillation cell (GS) method below.

10. GS - Grab Radon/Scintillation Cell
For this method, a skilled operator draws air through a filter to remove radon decay products into a scintillation cell either by opening a valve on a scintillation cell that has previously been evacuated using a vacuum pump or by drawing air through the cell until air inside the cell is in equilibrium with the air being sampled, then sealed. To analyze the air sample, the window end of the cell is placed on a photomultiplier tube to count the scintillations (light pulses) produced when alpha particles from radon decay strike the zinc sulfide coating on the inside of the cell. A calculation is made to convert the counts to radon concentrations.

11. SC - Three-Day Integrating Evacuated Scintillation Cell
For this method, a scintillation cell is fitted with a restrictor valve and a negative pressure gauge. Prior to deployment, the scintillation cell is evacuated. At the sample site, a skilled technician notes negative pressure reading and opens the valve. The flow through the valve is slow enough that it takes more than the 3-day sample period to fill the cell. At the end of the sample period, the technician closes the valve, notes the negative pressure gauge reading, and returns with the cell to the laboratory. Analysis procedures are approximately the same as for the GS method described above. A variation of this method involves use of the above valve on a rigid container requiring that the sampled air be transferred to a scintillation cell for analysis.

12. PB - Pump-Collapsible Bag (1-day)
For this method, a sample bag impervious to radon is filled over a 24-hour period. This is usually accomplished by a pump “Programmed” to pump small amounts of air at predetermined intervals during the sampling period. After sampling, analysis procedures are similar to those for the GB method.


13. CW - Continuous Working Level Monitoring
This method encompasses those devices that record real-time continuous measurement of radon decay products. Radon decay products are sampled by continuously pumping air through a filter. A detector such as a diffused-junction or surface-barrier detector counts the alpha particles produced by radon decay products as they decay on this filter. The monitor typically contains a microprocessor that stores the number of counts for predetermined time intervals for later recall. Measurement time for the Program measurement test is approximately 24 hours.

14. GW - Grab Working Level
For this method, a known volume of air is pulled through a filter, collecting the radon decay products onto the filter. Sampling time usually is 5 minutes. The decay products are counted using an alpha detector. Counting must be done with precise timing after the filter sample is taken. The two counting procedures most commonly used are the Kusnitz and the Tsivoglou methods described in the Indoor Radon and Radon Decay Product Measurement Device Protocols.

15. RP - Radon Progeny (Decay Product) Integrating Sampling Unit
For this method, a low-flow air pump pulls air continuously through a filter. Depending on the detector used, the radiation emitted by the decay products trapped on the filter is registered on two thermoluminescent dosimeters (TLDs), an alpha track detector, or an electret. The devices presently available require access to a household electrical supply, but do not require a skilled operator. Deployment simply requires turning the device on at the start of the sampling period and off at the end.The sampling period should be at least 72 hours. After sampling, the detector assembly is shipped to a laboratory where analysis of the alpha track and electret types is performed using procedures described for these

devices (AT, EL, and ES) elsewhere in this appendix. The TLD detectors are analyzed by an instrument that heats the TLD detector and measures the light emitted. A calculation converts the light measurement to radon concentrations.

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When you're dealing with a Radon reduction system, your choice in contractors does make a difference.  Not all Radon reduction systems are built the same.  At American Radon Services of Virginia LLC we use quality parts that are installed by certified technicians all backed by our 10-year warranty.


American Radon Services of Virginia LLC is a cerified Radon Measurement Specialist.  Everyone should have their home tested for Radon regardless of where you live.  Learn about all the possible Radon Tests and contact us to help you choose which testing method is best for you.

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We'll answer all your Radon related questions as well as provide you with all the necessary resources to keep you and your family safe.   American Radon Services of Virginia LLC is a certified Radon Measurement and Mitigator serving Virginia, Maryland and Washington D.C.

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American Radon Services of Virginia LLC provides service in the Virginia, Maryland and Washington D.C.  area.  Our after sales service is tops in the industry.  We service all radon fan models and offer affordable maintenance contracts that fit your budget.


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American Radon Services of VA LLC

8814 Dundee Dr.

​Fredericksburg, VA 22408

T. (540) 455-4961

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