Monday, 27 October 2014 16:00

Radon Measurement Devices: Five Tips Choosing the Right Devices

MeasDevices 1 aIndividuals planning on entering the radon field often call with questions about which device they should use. After all, there are a lot to choose from and it can be a little daunting. So, in this post we thought we would share some tips for our perspective students.

Tip #1: Complete a radon measurement course before committing.
Radon measurement device manufacturers are a reputable group.  However, they have a natural bias for their particular device.  So, the first tip is to complete your radon measurement course before purchasing a device.  The entry level radon measurement course provides a solid overview of the different categories of measurement devices dealing with environmental factors that can affect them, best applications, etc.  Being an informed buyer can significantly improve your chances of getting the right device for your business plan.  Plus, you will be more knowledgeable of the terminology when reviewing specifications of different providers.

Tip #2: Determine who is going to generate the radon measurement report.
There are two basic ways that a radon measurement result is determined.  They both involve you deploying and retrieving the device and insuring that placement protocols and proper environmental conditions are met during the test period.  The difference stops at the point of retrieval where a device can be shipped to an independent laboratory for analysis or you can analyze yourself.

Radon Measurement Devices analyzed by an independent laboratory:
In the case of having the device analyzed by a third party lab, the lab maintains calibration of detection equipment, goes through quality assurance measures that you don’t have to which can reduce your liability.  In short, it reduces a lot of the burden on you.  On the other hand, the time needed to ship the devices and obtain the reports may be longer than what you want.  If you are doing testing at the time of real estate sale, an extra day or two could be critical.  But if you are testing schools or apartment buildings where time is not as critical, these types of devices have great application and are very cost-effective.  Many radon inspectors use these devices as back up to their more sophisticated measuring devices, whether for quality checks or when they need to test more locations than they have machines for.  Common examples of this kind of measurement devices are short-term activated charcoal, liquid scintillation, or long-term alpha track detectors.

Radon Measurement Devices you analyze yourself:
There are many devices that you can push the buttons or use ancillary equipment to obtain the test result without sending it to a laboratory.  In fact, some of them allow you to obtain these results before you even leave the house if you wish.  These are very commonly used by inspectors conducting tests at the time of resale, where time is of the essence or by mitigation contractors who want to verify pre and post mitigation radon levels. 

If you use a self-analyzed device, recognize you are now functioning as a laboratory (or a Standard and Analytical Service Provider) and there are more requirements you have to follow, such as:

  1. Passing a performance test every two years (where you ship your device to an approved chamber for a blind comparison),  
  2. Having your device calibrated once a year,
  3. Paying additional certification fees to have a laboratory style credential,
  4. Submitting periodic reports to state agencies where required

That isn’t to say that you should avoid devices you can analyze yourself.  In fact, many radon professionals use these devices because of their ease and speed.  However, be aware of the additional administrative requirements -- and one other thing:  If you have only one device you can only measure one house at a time.  This is why many folks have multiple monitors or have a backup supply of other devices from an independent lab.

Examples of devices you can analyze yourself are continuous radon or radon decay product monitors and Electret Ion Chambers.

Tip#3: Radon measurement Devices: Bells and Whistles:
Assuming you select a device that is approved by the credentialing body you plan to be certified under (state or national).  They can all measure radon or radon decay products with “acceptable” accuracy.  What is different about many of them will be the bells and whistles that tell you things about the environment of the test or how the data is output.

The more sophisticated devices like continuous monitors will not only provide the overall average (which is what your recommendations are based upon), they can also indicate hourly changes in radon which can be informative for determining radon entry patterns as well as possible test interference.  Many will also provide additional information such as room temperature changes or device movement.  Note that these bells and whistles do not improve the accuracy of the actual measurement but rather improve your confidence that the device was not tampered with.

There are also differences in how the data is output.  Some provide a paper print out.  Some allow data to be downloaded to your computer, and some will actually create a full report.  In fact, there are now cloud based approaches where the data is uploaded to the internet and fancy reports are generated with data stored offsite.

So look at the bells and whistles as to what makes sense as to how you plan to conduct business rather than to the accuracy of the actual measurement.

Tip#4: Finding Approved Radon Measurement Devices
Just because a manufacturer says in a glossy Internet ad that their device can measure radon, it doesn’t mean that it has been proven to do so.  As a certified radon measurement professional, you are to use devices that are “Approved” by your certifying body.   Whether the certifying body be NRPP, NRSB, C-NRPP or a state agency; they all operate from a list of approved devices that have gone through rigorous third-party testing via a nationally recognized protocol.  Lists of approved devices can be viewed at each of their respective websites and are identified by manufacturer as well as the specific device.  Make sure the device and not just the manufacturer is on those lists.

If you are going to acquire devices from a third-party lab it is equally important is make sure the lab is also certified as an approved Analytical Laboratory -- meaning they have demonstrated their capabilities and maintain Quality Assurance and Quality Control programs.

Tip #5: Radon Measurement Quality Control and Quality Assurance
Regardless if you analyze the radon measurement device yourself or you utilize a third party laboratory, you still need to employ your own program for verifying the quality of the measurement devices you use.  In other words, you need to institute a program of assessing the precision of your devices by comparing the results of periodic duplicate measurements, identifying storage or shipping exposures by measuring unexposed devices (blanks), and you need to determine overall accuracy by occasionally sending in devices to a radon chamber and comparing the reported values to known values that existed in the chamber (spiking).

Choosing the Right Radon Measurement Device
Choosing the right radon or radon decay product measurement device may seem daunting at first.  It really isn’t that bad as long as you are knowledgeable of the devices, their uses, and the administrative requirements for the different devices.  That is why we recommend taking a radon measurement course first before committing.  We thoroughly enjoy talking to students after they complete our courses to kick around their business’ plans.  Then, with a solid technical foundation and a little advice, they can approach the manufacturers and labs with confidence.

If you want to discuss this further, do not hesitate to give us a call
Doug Kladder
800-513-8332

Read 43666 times Last modified on Wednesday, 16 December 2015 09:09
Doug Kladder

Director of Center for Environmental Research & Technology, Inc. (CERTI).