Radon testing types?

Hello, I was wondering if anyone could give advice on whether I should use a lab to process a radon test, or if short-term testing devices were accurate enough? Thank you in advance!

First, you need to understand what the differences are. Have you taken and completed any Radon courses yet? Whether your area requires it or not, you need to understand what you are doing. Do Not attempt to provide Radon testing services until you do.
Good luck!

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As Jeffrey noted, make sure you have the proper training. Both Home - National Radon Safety Board (nrsb.org) and AARST-NRPP are good sources for training and testing device information.

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both tests would be short -term tests. electronic tests are better in the way it will show spikes or falls in the readings by the hour. with a charcoal type test it will only capture the highest level in the charcoal to be read by a lab. and reports are more instant using a CRM. as client does not have to wait for the lab test to come back.
a home owner can just put the charcoal test outside till you are to return. the test will come back with pretty low levels.
With a CRM, yes the home owner can move the unit, but you will know it was moved. and a new test can be paid for again and completed. as long as the unit you buy has motion detection. Mine has GPS built into it.

The one I was looking at has a gps in it, and an app to help with the report, but I wasn’t sure is lab tested inspections were a must or not. I prefer not to go through a lab, as I mostly deal with houses flipping investors, but I wanted to know if I was required or not, first. Thank you so much!

You can get the ecosense radon eye pro for $715.50 with a discount through Nachi.

Actually not true. Charcoal like electrets change continuously over the exposure period. This gives a true exposure reading over the test period (48hrs for a RE transaction). Electronic tests only sample (typically every 30 min.) 96 times during a 48 hour period. All you are interested in is the average number. Spikes and falls in the readings are misleading and wile they reflect anomalies at the time of individual readings they simply do not contain enough information to be accurately explained (absent temperature, pressure, stack effect, door openings, etc.)

The explanation quoted suggests that charcoal or electrets just offer a peak reading. Not true. A good analogy is photographic paper. Left outdoors the peak light exposure may occur at noon but the paper will darken continuously all day indicating total light exposure over a specific time period. If, on the other hand, you only expose the paper twice every hour you will get a different result. (the average light intensity over the period might be the same, but what about all those missing samples between exposures).

Another example is a DMM with min, max. avg. capabilities. and this demonstrated the shortcomings of electronic Radon monitoring. The voltmeters MAX reading and the AVG reading over a given time period will be two different numbers. The accuracy of the AVG readings will depend entirely on the number of samples taken (sample rate) More is better.


One of the most popular CRM’s ever…

Not sure E-perm system is approved for real estate transactions. Do you need to use 2 like you do with charcoal canisters?

I know it’s the cheaper way to go, as you only need 1 reader. But my crm’s have a ±10% accuracy rate and measure every 10 minutes.

Eperm is approved and more accurate.

Not at all cheaper, it will cost you about 4 Grand to get started.

10 % of what? It could be a huge error.

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I spent 4 grand on my crm’s and I can only do 5 tests at a time. Your e-perms are cheaper in the long run. And just as accurate. But only give one 48 hour reading.
I’m not going to argue about it. To each their own.

Nothing to argue about. I can do 5 tests at one time and each E-perm is reusable. I can do short term or long term tests. Sounds like you know very little about E-perms.


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I did research on e-perms. But I didn’t like the test results just being one number. But I guess the average # is really all that counts in the long term I guess.
I also liked that you can do more tests by the number of cheaper electrets you have. But I have my 5 crm’s I’m using now. But if I get more requests for Radon in the future I may pick up a E-perm kit. Just need to make sure I get the motion detector that goes in the case.
As homeowners like to move it to get better results if they know they have high levels.

Homeowners ASSUME, but have no idea what actually occurs. Use that to your advantage. I post this notice at the front and rear house door, garage door, kitchen counter, at the doorway to the room the test device(s) are located, and on the tripod/stand (mine) that the devices are placed upon. I have never had any concern with my devices being tampered with!

Radon Test In Progress CEPI.doc (34 KB)

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I have some safety yellow door hangers I post on doors and on my tripod also.

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NRSB approved radon testing devices are reliable between each other. “Accurate enough” is not a question you should be asking. You need to get training and develop a Quality Assurance program, which includes regular testing of your procedures and devices. You need to perform duplicates, crosschecks, blanks, and spikes, depending on your device. Don’t know what that is, get training. Like home inspecting, your job is to be a professional. You need to be able to document and defend that your readings are reliable.

Best argument for using a Lab…

With carbon canisters or pouches, which are sent to a lab, you still have to perform spikes and blanks. It’s part of your MN license requirements.

Never said it wasn’t, but it does eliminate all the BS with each and every CRM you use!! That time savings alone is a no brainer!!