Charcoal vs. CRM

I was recently asked by a client to prove that the charcoal test kits are as accurate as CRM. This is after a verbal explanation. He wants some documentation.

Does anyone have something already typed up or a link?

I am awaiting an email response from AirChek. Thanks!!

Is it charcoal or Teflon. I think most labs are using Teflon now because it’s more accurate.

A CRM is only as accurate as the user who follows a strict maintenance protocol as defined by the Manufacturer, EPA, and any local governing authority.

Ask the supplier of your devices.

With regard to accuracy only, they both have some advantages. Charcoal’s advantages with regard to accuracy are:

  1. Charcoal collects the actual radon gas… it’s inside the charcoal. The radon had to come from somewhere.

  2. You can use numerous charcoal kits, including blanks, duplicates, kits in different parts of the home, and even kits being analyzed by different labs to cross check everything.

The advantage CRM’s have is that the integrate evenly over time. Charcoal kits are biased toward the end of the test due to half life.

Good info here on the different methods.

If we put a couple charcoal canisters, a pair of electrets and some CRMs in a closed room all sitting on a table and left them there for 4 days guess what we’d get?
A bunch of different results.
There is little chance the numbers would all come out the same.

If we performed the same test with the same devices and did a 3 month test then they would probably agree with one another with only slight variations.

The short term testing we do for real estate transactions is just a rough indication of radon levels.
And I tell my clients all that upfront.

What if we do a short term test and the average comes back at 3.8?
If the client seems concerned then I advise them to do a 3 month test after they move in to get a real idea of what’s going on.
I send them to to purchase a long term test kit.

You may get different results but all should be pretty close or something is wrong with one or more devices.

In my state protocol calls for a longer term test.

Define “pretty close”!

Share some data high low and mean